Institutional discrimination refers to the systemic and embedded practices within social organizations that disadvantage certain groups. A primary mechanism is the 'old boys' network' or homosocial reproduction, where those in power (gatekeepers) favor individuals who share their background, thereby perpetuating existing hierarchies and excluding marginalized groups from positions of influence.

Environmental racism refers to the disproportionate placement of hazardous waste sites, industrial pollution, and toxic facilities in communities populated primarily by people of color. In the United States, sociological research has consistently shown that African American communities are more likely to be located near environmental hazards, leading to significant health disparities and social inequality compared to other demographic groups.

Intersectionality is a theoretical framework that examines how various social and political identities combine to create unique modes of discrimination and privilege. It highlights that individuals do not experience inequality through a single lens, but rather through the overlapping and interdependent systems of oppression.

Affirmative action refers to policies designed to increase the representation of historically marginalized groups in areas like employment and education. Because these policies involve complex questions of equity, meritocracy, and social justice, they have remained a persistent and intense subject of public and political debate in many societies, reflecting deep-seated disagreements regarding the best methods to achieve social equality.

There is a notable disparity between urban and rural literacy rates in Pakistan. Data indicates that urban areas generally maintain higher literacy rates, such as 63%, compared to rural areas, which often hover around 34%. This gap reflects unequal access to educational resources, infrastructure, and socio-economic opportunities between the two settings.

Corporate crime often involves complex organizational structures, making it difficult to assign individual liability. Victims may be unaware of the harm caused, such as in cases of environmental pollution or financial fraud. While option D is the correct answer in the context of this question, it is worth noting that corporate crimes often cause significant, widespread harm, sometimes exceeding the impact of individual street crimes, despite being harder to prosecute.

The 'Matthew Effect' in sociology refers to the concept that 'the rich get richer and the poor get poorer.' When applied to social policy, it describes how middle-class or wealthier individuals, who possess more social capital and information, are often better equipped to access and utilize public services, thereby capturing benefits originally intended for the most vulnerable populations.

Social exclusion refers to the process by which individuals or groups are pushed to the margins of society, preventing them from participating fully in social, economic, and political life. Tax avoidance, gated communities, and homelessness are all phenomena that relate to social stratification, inequality, or the restriction of social participation, thus they are often discussed within the framework of social exclusion.

Richard Wilkinson's research, particularly in 'The Spirit Level', argues that income inequality is a major driver of health and social problems. While the provided answer key selects 'social integration', Wilkinson's broader thesis emphasizes that the degree of social inequality is the fundamental determinant of health disparities in developed nations. This discrepancy suggests a potential conflict between the source key and established sociological literature.

Social inequality is a multidimensional phenomenon. It is structured by various intersecting factors, including socioeconomic class, gender, race, and ethnicity, which collectively influence an individual's access to resources, opportunities, and social standing.