How did buddhist monks protest diem’s religious intolerance

Initially through demonstrations and then by setting themselves on fire.

Explanation:

Initially, the Buddhist monks protested through demonstrations during the political and religious crisis in South Vietnam. The tension lasted from May to November 1963 against the President Ngo Dinh Diem. But, the tensions became very severe when a monk set himself on fire on a road and the pictures of that incident went viral across the country and the world in June 1963. Eventually, it lead to the fall of the government in November 1963.

the answer to this question is d