The correct answer is D. Vietnam War
Step-by-step explanation:
Tim O'Brien is an American writer who was born in 1946 and who is mainly known due to his novels and literary works. During this youth, O'Brien participated in the Vietnam War that took place from 1955 to 1975 and although his participation in the war was brief (from 1969 to 1970) this influenced greatly his career as a writer after the world. Indeed many of his works contain facts related to this war mix with fictional elements. This includes the short story "Ambush" in wich Tim O' Brian recounts one of the events (an ambush) in which he participated during the Vietnam War. Therefore, Ambush" by Tim O' Brian is based on the Vietnam War.