Barley contains the vitamin cytocin, but not in a form the body can ab

Barley contains the vitamin cytocin, but not in a form the body can absorb. Pellagra is a disease that results from cytocin deficiency. When barley was introduced into southern Europe from the Americas in the eighteenth century , it quickly became a dietary staple and many Europeans who came to subsist primarily on barely developed pellagra. Pellagra was virtually unknown at that time in the Americas, however, even among people who subsisted primarily on barley.

Which of the following, if true, most helps to explain the contrasting incidence of pellagra described above?

A. Once introduced into southern Europe, barley became popular with landowners because of its high yields relative to other cereal crops.
B. Barley grown in the Americas contained more cytocin than barley grown in Europe did.
C. Traditional ways of preparing barley in the Americas convert barley's cytocin into a nutritionally useful form.
D. In southern Europe, many of the people who consumed barley also ate cytocin-rich foods.
E. Before the discovery of pellagra's link with cytocin, it was widely believed that the disease was an infection that could be transmitted from person to person.