Which of the following war decided the English as the ultimate rulers of India?

The Battle of Buxar was fought on 22 October 1764 between the forces under the command of the British East India Company, led by Hector Munro, and the combined armies of Mir Qasim, Nawab of Bengal till 1763; the Nawab of Awadh; and the Mughal Emperor Shah Alam II. The battle was fought at Buxar, a "small fortified town" within the territory of Bihar, located on the banks of the Ganges river about 130 kilometres (81 mi) west of Patna; it was a decisive victory for the British East India Company.