Choose your reply from the options at the end. Does "The Black Legion, a secret vigilante group, was active in the Detroit area in the 1930s, when one-third of its estimated 20,000 to 30,000 members in Michigan were based in the city." contain the correct answer to "By which decade had the KKK become very active in Detroit?"
Possible answers:
[a]. yes.
[b]. no.
[b].