How Were Black Nurses Exploited During the Late Nineteenth and Early

How were black nurses exploited during the late nineteenth and early twentieth century?

A) Generally, whites did not allow black women to become nurses.
B) Black physicians would often hire them out to individuals but refuse to allow them to keep their pay.
C) Black nurses were never paid for their services.
D) Black nurses were allowed to work only on the front lines during wartime, and only under the most dangerous conditions.