Answer:
D. Potatoes
Step-by-step explanation:
Potatoes was the main crop that grew rapidly and helped them survive and thrive in the Andes Mountains. They cut terraces in the side of the mountains to grow potatoes.
Maize was also grown there yet the reason I say that this is not the answer is because it is considered elite class food that is normally given to the higher class like the "Maiden". Which means it would not help all the incas thrive.
Have a wonderful day ;)