Explanation:

- First Carnatic War: This was part of the Anglo-French struggle in the south, but it did not determine the fate of the French in India.

- Battle of Buxar: Fought in 1764, it was between the British and Indian rulers, not the French, hence irrelevant to the French fate in India.

- Battle of Plassey: Took place in 1757 between the British and Nawab of Bengal. It established British dominance in Bengal but wasn't focused on the French.

- Battle of Wandiwash: This battle in 1760 was decisive for the French in India. The British defeated the French, leading to their decline in India.

Answer: Option 4 - Battle of Wandiwash