What is the main idea of this paragraph about Benjamin Banneker? At a time when African Americans were shackled by the worst ways of segregation, Benjamin Banneker broke free to become the first African American scientist in America. What makes his story remarkable is that he became a distinguished mathematician, astronomer, and natural scientist with no formal training.

A.
Banneker was a professor of mathematics, astronomy, and science.
B.
Banneker achieved much within a short span of time.
C.
Banneker was the only man who broke free of the shackles of segregation in America.
D.
Banneker lacked formal training, yet his achievements are notable.