Which U.S. territory, now a state, was invaded and temporarily occupied by the Japanese Army during World War II?

The correct answer is Guam. During World War II, Guam was invaded and occupied by the Japanese Army shortly after the attack on Pearl Harbor in December 1941. The occupation lasted until 1944 when American forces returned and liberated the island. This historical event played a significant role in the Pacific Theater of the war.

Hawaii, although attacked in December 1941, was never fully occupied by enemy forces. Puerto Rico and Alaska also faced no invasion or ongoing occupation from Japanese troops during the war. Understanding this context helps clarify why Guam is the answer, as it directly experienced both invasion and temporary occupation during that conflict.