Question

What was one effect of Jackie Robinson’s joining Major League Baseball?
Other professional sports became segregated.
Other African Americans refused to watch Robinson play.
Other minorities began to play professional baseball.
Other minorities saw that integration was too difficult.

Answer 1

Other minorities began to play professional baseball.

Jackie Robinson breaking MLB's color barrier in 1947 helped pave the way for greater integration of the sport and opened opportunities for other minority players to join professional baseball.