PT 31 S2 Q11

Several thousand years ago, people in what is now North America began to ... ...

Which one of the following, if true, most helps to explain why the people mentioned continued to grow corn as their staple grain crop?
(A) The variety of corn that the people relied on as their staple grain produced more food than did the ancestors of that variety.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: "Resolve/Explain" Questions, Set 1