By the late 1920s, labor unions - a. began to adopt policies of violence. b. weakened in membership. c. no longer segregated. d. were growing rapidly.

The answer is B. Labor unions initiated to act in America throughout colonial America but increased strength in the 1820's and were very prevalent during the post-civil war era, and increased popularity with miners, steel and fabric mill labors in the 1910's. The Unions acceptance and membership weakened in the 1920's after their main approval and association in 1919. Unions chosen back up in 1929 when the economy started to go bad.