Which of the following, if true, most helps to explain the difference mentioned above? A. Prohibition of hunting of waterfowl is easier to enforce in areas under cultivation than in wild lands. B. Most geese and swans nest and breed farther north than ducks do, in areas that still are not cultivated. C. Land that has been harvested rarely provides food suitable for waterfowl. D. Goose and swan populations decline in periods of drought, when breeding sites are fewer. E. Because they are larger than ducks, geese and swans have a harder time finding protected nesting sites in areas that are cultivated.