The correct option is C Vaishyas
The Brahmins were priests or teachers. They were considered to be at the top of the hierarchy, followed by the Kshatriyas, who belonged to a warrior caste. Then came the Vaishyas, who basically belonged to the working category like farming or trading. In the end came the Shudras, who were the labour category. Another social group that was considered inferior to Shudras was the so called untouchables.