How would a student justify inferring that “indigenous” means “originating in a particular region”?

There exists the same question that has the following choices.

A. The word root “gen” means “earth,” and the suffix “-ous” means “someone who does something.”
B. The word root “gen” means “birth,” and the suffix “-ous” means “having the quality of something.”
C. The word root “gen” means “body,” and the suffix “-ous” means “the state or condition of something.”
D. The word root “gen” means “rule,” and the suffix “-ous” means “being filled up with something

The correct answer is letter B. The word root “gen” means “birth,” and the suffix “-ous” means “having the quality of something.”