Which of the following is an example of racial-steering?

a. Real estate agents directing white clients to look for housing in certain neighborhoods, and non-white clients to others.
b. The Trail of Tears, when the United States government forced Native Americans to permanently leave their homes and territory.
c. Kiki being told she'll be bad at math because she is a girl.
d. Jose's parents not allowing him to date Martha because she is of a different race.