Answer: A. Navajo Indians in the U.S. Marine Corps developed an unbreakable code using their native language.
Navajo is a language that is not written and is very complex with its incomprehensible syntax, tonal qualities and especially the dialects. That is the main reason that Navajo language was used to secure communications during the war.
Explanation:
It is the right distance from the Sun, it is protected from harmful solar radiation by its magnetic field, it is kept warm by an insulating atmosphere, and it has the right chemical ingredients for life, including water and carbon.
