Question ID:PT31 S2 Q11 Passage:Several thousand years ago, people in what is now North America began to grow corn, which grows faster and produces more food per unit of land than do the grains these people had grown previously.  Corn is less nutritious than those other grains, however, and soon after these people established corn as their staple grain crop, they began having nutrition-related health problems.  Yet the people continued to grow corn as their staple grain, although they could have returned to growing the more nutritious grains.  Stem:Which one of the following, if true, most helps to explain why the people mentioned continued to grow corn as their staple grain crop? Correct Answer Choice:EChoice A:The variety of corn that the people relied on as their staple grain produced more food than did the ancestors of that variety. Choice B:Modern varieties of corn are more nutritious than were the varieties grown by people in North America several thousand years ago. Choice C:The people did not domesticate large animals for meat or milk, either of which could supply nutrients not provided by corn. Choice D:Some of the grain crops that could have been planted instead of corn required less fertile soil in order to flourish than corn required. Choice E:The people discovered some years after adopting corn as their staple grain that a diet that supplemented corn with certain readily available nongrain foods significantly improved their health.