What years did World War II span?

World War II is widely recognized as occurring from 1939 to 1945. This timeframe is significant because it aligns with critical events such as the invasion of Poland by Germany in September 1939, which marked the beginning of the war in Europe. The conflict involved many nations and ultimately led to a global confrontation that lasted until the surrender of Japan in September 1945, which is viewed as the war's conclusion.

Other options have timeframes that either begin or end too early or too late compared to the historically accepted dates. The timeline chosen correctly encapsulates the full scope of the war's impact and the involvement of various countries during those years.