单项选择题

Visiting to an authentic (正宗的) Mexican restaurant is a good way to discover the richness of Mexican cuisine. To begin, you may order some tasty appetizers like cheese quesadillas. For the next course, you can’t miss a chicken chimichanga, which has a delicious, mild flavor. Another choice is a beef enchilada. Covered with spicy tomato sauce and topped with cheese, it will set your taste buds dancing.
To complete your Mexican meal, try a scoop of fried ice cream. Besides cooling you down, it will leave you wondering how the cook managed to deep fry the ice cream without melting it.
In ancient times, ______ was the most important food for Indians of the area that is now Mexico.

A. chicken
B. beef
C. beans
D. corn