The correct answer is B) 1809.
Velu Thampi Dalawa was a Malayali warrior and statesman who led a major revolt against the British East India Company in Travancore in 1809. The revolt was unsuccessful, and Velu Thampi Dalawa was killed in battle. However, the revolt is remembered as a significant event in the history of Kerala.
Option A) 1790 is incorrect because the Travancore-Kochi War of 1790 was fought between the Kingdom of Travancore and the Kingdom of Cochin. The war was not a revolt against the British East India Company.
Option C) 1857 is incorrect because the Indian Rebellion of 1857, also known as the Sepoy Mutiny, was a major uprising against the British East India Company in India. The rebellion was not fought in Travancore.
Option D) 1921 is incorrect because the Malabar Rebellion of 1921 was a major uprising against the British Raj in Malabar, India. The rebellion was not fought in Travancore.