请教：大全Sec13 - 14

1.                             Researchers have questioned the use of costly and experimental diagnostic tests to identify food allergies, such as milk, that supposedly disrupt normal behavior.fficeffice" />

(A) to identify food allergies, such as

(B) to identify food allergies, like

(C) to identify food allergies, such as to

(D) for identifying food allergies, like that of（C）

(E) for identifying food allergies, such as for

答案是C。请问C到底省略了什么，identify还是allergy？如果是identify,那算是什么用法呢，以前怎么从来没有看到过？还有其他类似的例句吗？