The choices can be found elsewhere and as follows:
A. being conquered by the Mayans.
B. Francisco Pizzaro's trap that helped capture and kill the Incan emperor and his men.
C. that the Spanish had superior weapons.
D. that the Spanish brought with them
I think the correct answer is option A. All of the following aided in the decline of Incan Empire except being conquered by the Mayans. Hope this answers the question.