Uninformed about students' experience in urban classrooms, critics oft

‘Such as standardized test scores’ is only an example and hence can not decide the verb. It is the singular ‘index’ that is related by the pronoun ‘that’ and hence, the verb has to be the singular ‘is’ – Drop A and B

In C, ‘an index, such as standardized test scores, that is called objective and can be quantified’ is too verbose at least by a couple of words in comparison to ‘a so-called objective index, such as standardized test scores, that can be quantified” in D and E

In E, the expression ‘that is quantified’ alters the intent of the text which means ‘that can be quantified’

D glides past these pitfalls smoothly and survives. However, the phrase ‘such as what is made’ is indeed unnecessary and one can always prefer ‘such as that” as in E. However, E has the fatal flaw of using the unacceptable ‘that is quantified’

However,Do you know something, the original post from Kaplan, as given below is different from this simulated one here . The Kaplan example has “ can be quantified” for all the choices, unlike in this text, which alters Choice E with ‘that is quantified’ which is materially wrong.

Look at this

A. an index, such as standardized test scores, that are called objective and can be quantified and overlook less measurable progress, such as that
B. an index, such as standardized test scores, that are called objective and can be quantified and overlook less measurable progress, such as what is made
C. an index, such as standardized test scores, that is called objective and can be quantified and overlook less measurable progress, such as what is made
D. a so-called objective index, such as standardized test scores, that can be quantified and overlook less measurable progress, such as what is made
E. a so-called objective index, such as standardized test scores, that can be quantified and overlook less measurable progress, such as that

In the Kaplan's case E is the OA and rightly so. But in the given one here, D IMO.