Which events led to the decline of the inca empire

(1)The civil war weakened the military of the Inca Empire.When Pizarro went to defeat them,they did not have enough army personnel or strength to fight back.Pizarro also took their Inca leader captive and killed him after receiving the ransom he had asked.

(2) The two sons of Huayna Kapac plunged the empire into a brutal civil war.Atahualpa and Huascar called on the mummified bodies of past Sapa Incas to assist them.The Incas believed,their rulers were living descendents of Inti,the Sun god.The civil seemed to end in 1532 when Atahualpa's army captured Huascar.

(3) With the arrival from Spain in 1532 of Francisco Pizarro seeking riches and his entourage of mercenaries,the Inca Empire was seriously threatened for the first time. Cheated into meeting with the conquistadors in a peaceful gathering,the Inca Emperor,Atahualpa was kidnapped and held for ransom.

(4) The Inca had already some contact with Europeans and many had died of European diseases.

(5)

your answer would be (b)