Britishers gained control of Rajmahal area by defeating

Answer: Option A

Rajmahal was the capital of Shuja during the Mugal period, and Dr. Gabriel Boughton was the British East India Company's envoy. In 1763, Major Adams and his company attacked Nawab Mir Qasim's property and took possession of the Rajmahal district. This shows that the British had finished their conquest of Rajmahal before gaining control of Bengal, Bihar, and Odisha's diwani (tax administration).