Q14:
Maize contains the vitamin niacin, but not in a form the body can absorb. Pellagra is a disease that results from niacin deficiency. When maize was introduced into southern LACE>EuropeLACE> from the LACE>AmericasLACE> in the eighteenth century, it quickly became a dietary staple, and many Europeans who came to subsist primarily on maize developed pellagra. Pellagra was virtually unknown at that time in the LACE>AmericasLACE>, however, even among people who subsisted primarily on maize.
Which of the following, if true, most helps to explain the contrasting incidence of pellagra described above?
- Once introduced into southern LACE>EuropeLACE>, maize became popular with landowners because of its high yields relative to other cereal crops.
- Maize grown in the LACE>AmericasLACE> contained more niacin than maize grown in Europe did.
- Traditional ways of preparing maize in the Americas convert maize’s niacin into a nutritionally useful form.
- In southern Europe many of the people who consumed maize also ate niacin-rich foods.
- Before the discovery of pellagra’s link with niacin, it was widely believed that the disease was an infection that could be transmitted from person to person.
选C
那位可以解释 以下么？？ | 
