The correct order of events is as follows:
- b. Germany invaded neighboring countries. (Starting in 1939, Germany invaded Poland and other countries in Europe.)
- c. Japan attacked Pearl Harbor. (This happened on December 7, 1941.)
- a. The United States declared war on Japan. (Following the attack on Pearl Harbor, the U.S. declared war on Japan on December 8, 1941.)
- d. Italy surrendered. (Italy surrendered in September 1943.)
So the correct answer is b, c, a, d.