1 he became the president of the republic of Vietnam
Why?
He was the final prime minister of the State of Vietnam, and then served as President of South Vietnam from 1955 until he was deposed and assassinated during the 1963 military coup.
In September 1931, they claimed Chinese soldiers had sabotaged the railway, and attacked the Chinese army (which had just executed a Japanese spy) The Chinese army did not fight back because it knew that the Japanese were just wanted an excuse to invade Manchuria
A is the only answer that makes any sense