**Rule**: For active sentences using the 'be going to' future form, the passive structure is **Object + is/am/are + going to be + V3**. The agent 'by them' can be omitted.

- **Correct Answer (c)**: The object 'the entire building' becomes the subject. The structure 'is going to be renovated' is the correct passive conversion. The agent 'by them' is correctly omitted.
- **Incorrect Answer (a)**: This changes the structure to the 'will' future.
- **Incorrect Answer (b)**: This is the passive of the Present Continuous tense.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Present Perfect.

**Rule**: For an interrogative sentence with the 'be going to' future form starting with 'Who', the passive structure is **By whom + is/am/are + object + going to be + V3?**

- **Correct Answer (b)**: 'Who' changes to 'By whom'. The object 'the event' is singular, so 'is' is used, followed by the object and the correct passive structure 'going to be managed'.
- **Incorrect Answer (a)**: This changes the structure to the 'will' future.
- **Incorrect Answer (c)**: This incorrectly changes the tense to the past.
- **Incorrect Answer (d)**: 'who' is the incorrect case; 'whom' is required after the preposition 'By'.

**Rule**: For a sentence in the Simple Past Tense, the passive voice structure is **Object + was/were + V3 + by + Subject**.

- **Correct Answer (d)**: The object 'the crops' becomes the subject. Since 'crops' is plural, 'were' is used. The adverb 'severely' is correctly placed before the past participle 'damaged'.
- **Incorrect Answer (a)**: This incorrectly changes the tense to Simple Present.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Past Continuous.
- **Incorrect Answer (c)**: This incorrectly changes the tense to Present Perfect.

**Rule**: For an active sentence using 'be going to' with two objects (indirect 'us' and direct 'a test'), either can become the subject in the passive form.

- **Correct Answer (d)**: Both (a) and (b) are correct passive transformations.
- In (a), the indirect object 'us' becomes the subject 'We'.
- In (b), the direct object 'a test' becomes the subject, and the indirect object is expressed as 'to us'.
- **Incorrect Answer (a)**: This is correct, but (b) is also a valid transformation.
- **Incorrect Answer (b)**: This is correct, but (a) is also a valid transformation.
- **Incorrect Answer (c)**: This changes the structure to the 'will' future.

**Rule**: For a Present Continuous Tense sentence, the passive structure is **Object + is/am/are + being + V3 + by + Subject**.

- **Correct Answer (d)**: The object 'kites' becomes the subject. Since 'kites' is plural, 'are' is used, followed by 'being' and the past participle 'flown'.
- **Incorrect Answer (a)**: This incorrectly changes the tense to Past Continuous.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Present Perfect.
- **Incorrect Answer (c)**: This incorrectly changes the tense to Simple Present.

**Rule**: For a Present Continuous Tense sentence, the passive structure is **Object + is/am/are + being + V3 + by + Subject**.

- **Correct Answer (a)**: The object 'me' becomes the subject 'I'. The verb form 'am being irritated' is correct for the Present Continuous passive for the first person singular.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Simple Present.
- **Incorrect Answer (c)**: This incorrectly changes the tense to Past Continuous.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Present Perfect.

**Rule**: For an interrogative sentence in the Past Continuous Tense starting with 'Who', the passive structure is **By whom + was/were + object + being + V3?**

- **Correct Answer (d)**: 'Who' becomes 'By whom'. The object 'the accounts' is plural, so 'were' is used, followed by 'being' and the past participle 'managed'.
- **Incorrect Answer (a)**: This incorrectly changes the tense to Simple Past.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Present Continuous.
- **Incorrect Answer (c)**: This incorrectly changes the tense to Past Perfect.

**Rule**: For an interrogative Present Continuous sentence with two objects starting with 'Who', either object can become the subject in the passive form, which starts with **'By whom'**.

- **Correct Answer (d)**: Both (a) and (c) are correct passive transformations.
- In (a), the indirect object 'you' becomes the subject, requiring the plural verb form 'are being taught'.
- In (c), the direct object 'mathematics' becomes the subject, requiring the singular verb form 'is being taught', and the indirect object is expressed as 'to you'.
- **Incorrect Answer (a)**: This is correct, but (c) is also valid.
- **Incorrect Answer (b)**: This has incorrect word order for a question.
- **Incorrect Answer (c)**: This is correct, but (a) is also valid.

**Rule**: For sentences with past modals (modal + have + V3), the passive structure is **Object + modal + have been + V3 + by + Subject**.

- **Correct Answer (b)**: The object 'your friend' becomes the subject. The past modal passive form 'ought to have been helped' is the correct construction.
- **Incorrect Answer (a)**: 'ought to be helped' is the passive form for a present modal ('ought to help').
- **Incorrect Answer (c)**: 'must' is a different modal, changing the meaning from moral obligation to strong deduction.
- **Incorrect Answer (d)**: This changes the modal structure entirely, altering the meaning to past necessity.

**Rule**: For a Present Continuous Tense sentence, the passive structure is **Object + is/am/are + being + V3 + by + Subject**.

- **Correct Answer (a)**: The object 'my car' becomes the subject. Since it is singular, 'is' is used, followed by 'being' and the past participle 'serviced'.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Past Continuous.
- **Incorrect Answer (c)**: This incorrectly changes the tense to Present Perfect.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Simple Present.