What was the direct cause of the U.S. entry into World War II?

Question

A.
the bombing of Pearl Harbor

B.
the invasion of Poland by Germany

C.
the capture of Belgium by Germany**

D.
the Battle of Britain

I think its b or c

Answer 1

I disagree. On December 7th 1941 the Japanese bomed pearl harbor Hawaii. Causing the U.S. to join allies in WWII