Endogamy is the social practice of marrying within a specific social group, caste, or ethnic group. This practice is often used to maintain group cohesion, preserve cultural traditions, or consolidate social and economic status within a community.

Historical demographic studies of the Victorian era indicate that marriages were often shorter than today, frequently ending due to the premature death of one spouse rather than divorce. An average duration of approximately 12 years reflects the high mortality rates prevalent during that period.

Polyandry is a specific form of polygamy where a woman is married to two or more men at the same time. This practice is relatively rare globally compared to polygyny, which is the marriage of one man to multiple women. Polyandry is often studied in the context of specific cultural and economic conditions where such arrangements provide social or survival advantages.

The question asks for the term describing a woman having multiple husbands. The correct sociological term for this is polyandry. However, the provided answer key is 'C' (polygyny), which refers to a man having multiple wives. This represents a factual conflict between the definition provided in the question and the answer key. Users should note that polyandry is the accurate term for the described scenario.

Fraternal polyandry is a form of marriage where two or more brothers are married to the same wife. This practice is historically documented in various cultures, such as in parts of Tibet and the Himalayas, often serving to keep family landholdings intact and prevent the fragmentation of property.

Exogamy is a social norm that requires individuals to marry outside of their own specific group, such as a clan, tribe, or village. This practice is often used to establish alliances between different groups, prevent incest, and promote social integration by expanding kinship networks beyond the immediate community.

Polygyny is a specific form of polygamy where one male has multiple female spouses at the same time. This practice is historically documented in various cultures worldwide, often linked to social status, economic resources, or specific religious and cultural traditions that permit plural marriage for men.

Polygamy is a marriage system involving multiple partners. The two main forms are polygyny (one man with multiple wives) and polyandry (one woman with multiple husbands). Note: The provided answer key 'D' is technically incorrect as it includes 'Monogamy', which is a distinct form of marriage, not a type of polygamy.

Monogamy is the practice of being married to only one person at a time. It is the most common form of marriage globally and is legally recognized in most modern societies, emphasizing a singular, exclusive partnership between two individuals.

Statistical data indicates a decline in formal marriage rates, particularly regarding first marriages since the 1960s, alongside an increase in single-person households. However, sociologists note that this does not necessarily signal a rejection of long-term commitment. The significant rise in cohabitation—couples living together in stable, long-term relationships without legal marriage—suggests that while the traditional institution of marriage is changing, the underlying social value placed on committed partnerships remains prevalent in contemporary society.