Solution:Battle of Ambur ( August, 1749):- The combined armies of Muzaffar Jung, chanda sahib and the French defeated and Killed Anwar-ud-din at the Battle of Ambur near Bellore in August, 1749. Muzaffar Jung became the Subedar of Deccan. Duplex was appointed Governor of all the Mughal territories south of the river Krishna. The Nizam surrendered some districts in the northern circars to the French. A French army under Busy was stationed in Hyderabad.Battle of Plassey (June, 1757):- Fought between Nawab of Bengal Sirajuddaula and the British Army. Bengal was in control of the British after Plassey. Mir Jafar was placed on the throne by Robert Clive. In exchange, Mir Jafar ceded an area of the South of Calcutta known as 24 Pargana to the British for their services and gifted 2,34,000 pounds to Clive as personal gift reward.
Battle of Wandiwash (January, 1760):- It occurred between French and British. French were defeated by the British. Sir Eyre coote was the leader of the British Army while French Croops were led by Count de Lally.
Battle of Buxar (October, 1764):- Fought between allied forces of Mir Qasim, Shujauddaula, Shah Alam II and the British British let by Hector Munro defeated the allied forces badly. Thus, option (b) will be the correct answer.