再问一道语法

Researchers have questioned the use of costly and experimental diagnostic tests to identify food allergies, such as milk, that supposedly disrupt normal behavior.  
(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
(E) for identifying food allergies, such as for

Key: C

C处的to identify...应该是不定式结构，那么such as to该怎样解释呢, 是省略吗：such as to (test) milk。不太清楚，请大家指点。

偶觉得应该是such as (to identify food allergies) to milk.

such as不仅可以接名词，还可以接很多成分，至少我见过接时间状语从句。

我查到了allergy to sth 是固定词组，这里的to 应该是介词。

谢谢waterpoo!

such as之后只是省略了allergies，而不应该是前面的to do不定式中的其他内容；

Such as 用来举例的。前面说Researchers have questioned the use of 。。。。to identify food allergies。。 那么such as后因该举例才对。所以还原后为such as the use of ... to identify milk allergy , that..... 其中that指带milk allergy 。

不知道对不对，请nn指正。