A) They were part of the Navajo "Code Talker" vocabulary to transmit secret messages.
During World War II, the Navajo language was used as a code to transmit secret messages between American troops. The Navajo Code Talkers were a group of Native American soldiers who used their language, which was unknown to the enemy, to create a code that was unbreakable. The code was so successful that it was used in every major battle in the Pacific theater of the war, and it was never broken by the Japanese. The terms you listed, such as "Japan," "planes," "transport," and "weapon," were all part of the Navajo Code Talker vocabulary.