Hawks in a certain region depend heavily for their diet on a particular variety of field mouse. The killing of field mice by farmers will seriously endanger the survival of hawks in this region.
Which of the following, if true, casts the most doubt on the conclusion drawn above?

A. The number of mice killed by farmers has increased in recent years.

B. Farmers kill many other types of pests besides field mice without any adverse effect on hawks.

C. Hawks have been found in other areas besides this region.

D. Killing field mice leaves more food for the remaining mice, who have larger broods the following season.

E. Hawks are also endangered because of pollution and deforestation.



OA D

Source: Princeton Review