It was in ______ that he decided to dedicate his life to the struggle against racial oppression.

A．the vagueness of his African ancestry
B．the unfair treatment of him at school
C．the miserable sufferings of the slaves
D．the inhibitions haunting his parents

A．the Civil War had eliminated racial discrimination in the U. S.
B．his grandmother could recite the history of the western world
C．Du Bois was considered something of a prodigy and very promising
D．his great-grandfather had fought in the American war of independence