Historically, the understanding of inequality in the social sciences…

The correct answer is Option (2) → Class, race and more recently, gender

Option (1) Caste, tribe and more recently, gender — Incorrect. Caste and tribe are the categories that received attention only later. They were not the notions that first dominated the study of inequality.

Option (2) Class, race and more recently, gender — Correct. The study of inequality in the social sciences was long dominated by class and race, and more recently by gender. Other categories such as caste and tribe came in only later.

Option (3) Class, caste and more recently, disability — Incorrect. Caste came into focus only later, and disability is not the recent addition. Gender is the category that joined class and race more recently.

Option (4) Race, religion and more recently, region — Incorrect. Religion and region are not among the dominant notions. Religion is a category still in need of attention, and caste and region is a formation likely to claim attention in future.