Assertion :The British dethroned Mir Qasim and reinstated Mir Jafar as the Nawab of Bengal.
Reason: Mir Qasim was independent in his outlook unlike Mir Jafar.
The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
Mir Qasim was independent in his outlook. After verifying the misuse of Dastakaths, he made all trade in Bengal tax free. This made the British to face the competition from the Indian Merchants. So they dethroned Mir Qasim and brought back Mir Jaffer to the throne. All this ultimately led to the Battle of Buxar. The Battle of Buxar happened in the year 1764. In this battle, Hectar Munro of the British defeated the combined forces of Mir Qasim. THE Nawab of Awadh took refuge in Rohilakhand and Shah Alam took the side of the British. Mir Qasim had to run away from the battle field.