For the civil services examination, UPSC provides a list of optional subjects. Candidates have to choose one optional for the mains exam.

Geography is the study of Earth's landscapes, environments, and the relationships between people and their surroundings, encompassing both physical and human aspects.

History is the study of past events, societies, and human experiences, providing insights into the complexities of the human condition and the forces that shape the world.

Sociology is the study of society, social behavior, and the interactions among individuals within social systems.