The correct option is B The battle of Buxar
The first major conflict of the British against an Indian power was in Bengal. The history of Bengal from 1757 to 1765 is the history of gradual transfer of the power from the Nawabs to the British. During this short period of eight years three nawabs, Siraj-ud-Daula, Mir Jafar and Mir Qasim ruled over Bengal but they failed to uphold the sovereignty of the nawab and ultimately the reign of control passed into the hands of the British. Finally Battle of Buxar established British supremacy in India.