Based on the article, which statement below explains why the Code Talkers were awarded the Congressional Medal of Honor?

a) Some of the Navajo left their reservations for the first time to join the Marines.
b) The Japanese caused the U. S. to enter the war when the bombed Pearl Harbor.
c) The Code Talkers’ unbreakable code was crucial to the WWII victory.
d) The Navajo Code talkers had to be brave to go to war.