What was one of the main reasons the portuguese and spanish failed at enslaving native people of the new world?

a. the natives staged a rebellion and won.
b. many of the natives were not good at farming.
c. the natives seem to work better under a wage system.
d. many of the natives quickly died from overwork and disease.

D. Many of the natives quickly died from overwork and disease.

Well technically both A and D could be correct. The natives rebelled because they did not want to be under their rule due to the encomienda system. D is the better answer though because along with bringing typhoid, the Europeans brought many other diseases that aided in the mass killing of up to 80 to 90% of the Native American population