prep有道题还是没搞懂

The list of animals that exhibits a preference of either using the right or the left hand (i.e., claw,
paw, or foot) has been expanded to include the lower vertebrates.
(A) exhibits a preference of either using the right or the left hand (i.e., claw, paw, or foot) has
been expanded to include
(B) exhibits the preference to use either the right or the left hand (i.e., claw, paw, or foot) has
been expanded and includes
(C) exhibit a preference in either using the right or the left hand (i.e., claw, paw, or foot) has
been expanded to include
(D) exhibit a preference for using either the right or the left hand (i.e., claw, paw, or foot) has
been expanded to include
(E) exhibit the preference as to either using the right or the left hand (i.e., claw, paw, or foot) has been expanded and includes

答案是D，请问nn这里的exhibit指代什么，为什么用复数哦？谢谢

that 是要紧跟现行词的，所以，紧跟animals,