The best option would be that "<span>The U.S. imposed a treaty that forced Latin American countries to democratize or face crippling sanctions," since it was never in American's best interest to force the democratization of the region. </span>
I dont see a document but i think i can still answer your question. Slaves were not considered people because they were owned by people and considered property. Slaves did not have rights like others and were not accounted for until the 3/5 act. And even then only 3 out of 5 slaves were counted to up the population but still did not have rights.
The correct answer is : D. weakening of the middle class