Answer: The correct answer is : b. served in the military and worked in war production.
Explanation: During the Second World War the government of the United States needed the help of the Navajo Indians. Given the need to create a secret military code that was not deciphered by the Japanese, the language of the Navajo Indians was used and code words were used since they did not have in their language many terms used in the war. 200 Navajo Indians were enlisted to act as key announcers.