The correct answer is false.
It is false that one of the most powerful Varnas were the Sudras.
The Varnas were the social classes of Hinduism. The Sudras were not one of the most powerful Varnas. They were the artisans and workers. They were hired by other social classes in India to do jobs and helped other people. The other Vadras of Hinduism were the Vaishyas, Kshatriyas, and the Brahmanas.