What problems did returning African American soldiers face after World War I?

A. Pressure to take railroad and farm jobs
B. Quotas and competition
C. The problems of success
D. Lynching and Ku Klux Klan violence

Knowing what I know about the treatment of African american during this period I'd say D, but I'm not sure. I'm assuming it's not A, because the rich white would probably prefer sending the African American population than their own children.