Answer:
D. it went against the ideals of freedom on which of the nation was founded
Step-by-step explanation:
A paradox is something that is self-contradictory. So, whichever answer choice shows a contradiction will be the answer.
Answer choice D states that the nation was founded on the ideas of freedom. Having slaves in a nation founded on freedom is contradictory because slaves have all of their freedom taken away from them. A nation based on freedom should not have people without freedom in it.