Answer:
A. did not know that the Japanese planned to attack Hawaii.
Step-by-step explanation:
The Pearl Habor attack by the japanese on the Americans was definitely an element of surprise to the Americans especially to the President Franklin Roosevelt. This is as result of the engagement of the american government with the Japanese government inorder to find a lasting peace in the Asian continent.
This attack triggered a series of event with the American government abandoning their neutrality in theongoing war then and to officially join the war inorder to protect their interest and defeat the Japanese.