Which statements describe an event that contributed to the fall of the Inca Empire? Select all that are correct.
A: Disease ravaged the Inca empire that the Spanish unknowingly carried
B: Pizarro took Atahualpa captive and then had him executed
C: A civil war had weakend the Inca people before the Spanish people arrived
D: The Spanish were unable to overpower the Incas with their superior weaponry