What event led to the US halting exports to Japan prior to World War II?

The choice regarding Japan's invasion of China accurately identifies a pivotal event that led to the United States halting exports to Japan prior to World War II. This invasion began in 1937 and marked a significant escalation in Japanese military aggression in Asia. The U.S. responded to Japan's expansionist policies and military actions, which threatened the balance of power in the region and the interests of the United States, particularly in terms of trade and stability.

In response to Japan's actions, the U.S. implemented economic sanctions and trade embargoes, particularly targeting critical supplies like oil and steel, which were essential for Japan's military operations. The intention was to curb Japan's aggression and compel a change in policy. This reaction laid the groundwork for escalating tensions that would ultimately contribute to the broader conflict of World War II, especially following Japan's subsequent military actions.

In contrast, other events listed, such as Germany’s invasion of Poland and Japan's attack on Pearl Harbor, occurred later in this timeline. Germany’s invasion of Poland in 1939 primarily impacted European dynamics and led to the official commencement of World War II in Europe, whereas the attack on Pearl Harbor in 1941 prompted the U.S. to enter the war but was not an antecedent event