The central claim of Benjamin Banneker's letter to Thomas Jefferson is option c. It is hypocritical to state that "all men are equal" in a country that permits slavery.
The Bill of Rights was adopted in 1791, but the rights it granted were withheld from Africans who lived as slaves. That same year, in August, Banneker challenges Jefferson with this letter. He points out that it is a contradiction between the rights granted in the Bill of Rights and the continuation of slavery. And it is also a contradiction to state that all men are equal in the eyes of God, and deny liberty to the slaves.