Which of the following draws a conclusion about the role of war in uniting Japan?

War, are united Japan and allowed to take over Korea, This made it an empire.
War United Japan in allowed it to take over Korea but this did not make it an empire.
War united Japan, but did not allow it to take over Korea.
War had no role in uniting Japan.

War, are united Japan and allowed to take over Korea, This made it an empire.