Conversation so far:
where did Ben Carson attend high school?
predominantly black Southwestern High School.
did he do well in high school?
Carson relates that as a youth he had a violent temper.
did he get into any trouble with the law as a teen?
CANNOTANSWER.
what is notable about his time in high school?
he protected white students in a biology lab after a race riot broke out at his high school in response to the assassination of Martin Luther King.
was he well liked in high school?
classmates, and neighbors who grew up with him told CNN in 2015 they did not remember the anger or violence he has described.

Question: what was his major course of study?
Self-contained rewrite: What was Ben Carson's major course of study?