a study of the cognitive abilities of white-faced capuchin monkeys (Cebus imitator), researchers neglected to control for the physical difficulty of the tasks they used to evaluate the monkeys. The cognitive abilities of monkeys given problems requiring little dexterity, such as sliding a panel to retrieve food, were judged by the same criteria as were those of monkeys given physically demanding problems, such as unscrewing a bottle and inserting a straw. The results of the study, therefore, Which choice most logically completes the text?

A) could suggest that there are differences in cognitive ability among the monkeys even though such differences may not actually exist.
B)
are useful for identifying tasks that the monkeys lack the cognitive capacity to perform but not for identifying tasks that the monkeys can perform.
C)
should not be taken as indicative of the cognitive abilities of any monkey species other than
C. imitator.
D) reveal more about the monkeys' cognitive abilities when solving artificial problems than when solving problems encountered in the wild.

A) could suggest that there are differences in cognitive ability among the monkeys even though such differences may not actually exist.