The correct option is B Brahmins
Traditionally, a person's caste was determined at birth and often resulted in restricted social mobility and fixed social hierarchies. At the top were the Brahmins, who were the priests and scholarly class of the society.
At the bottom were the scheduled castes and tribes, commonly known as ‘Dalits’ or ‘Harijans’. They were considered to be outside the caste system or ‘Untouchables’.