Why was the attack on Pearl Harbor significant?

a$)$ It demonstrated the Japanese naval commander's belief that the only way Japan could defeat the US was through a long war.

b$)$ It showed that the United States was too quick to lift embargoes on Japan.

c$)$ It was a surprise attack that immediately caused the US to declare war and brought the isolationist movement to an end.

d$)$ All of the above are true.