The decline in students' perfomances on state-wide tests

Question

The decline in students' perfomances on state-wide tests ha has been documented by a number if researchers, but what is more difficult to determine are  the root cause of this decline, the reason for the lack of equality between school systems and the degree to which teachers can be held accountable

(A) has been documented by a number of researchers, but what is more difficult to determine are
(B) has been documented by a number of researchers, but what is more difficult to determine is
(C) have been documented by a number of researchers, but what is more difficult to determine are
(D) is documented by a number of researchers, but what has been more difficult to determine are
(E) are documented by a number of researchers, but what is more difficult to determine is

Please explain logic !

OA: (B)

lagomez · Answer

Subject is "decline" so that eliminates c, d, and e
difficult to determine is....In this part an "is" is needed because of the subject "cause"
They try to make the sentence more confusing by putting the verb before the subject

dimitri92 · Answer

the decline .... has --> this is correct and agree is number
the decline .... have/are --> does not agree in number

this eliminates .. C & E

.. what is more difficult to determine are the root cause of this decline
flip this sentence to see whether to use is or are
the root cause of this decline IS/ARE more difficult to determine --> i hope it is clear now .... use IS

this eliminates .. A, C & D

B it is

oh, and, don't forget to press KUDOS if you like the explanation

zisis · Answer

kudos ! the flip the sentence trick will be useful for future probs :idea:

seekmba · Answer

OA is B

The decline in students' perfomances on state-wide tests  has been documented by a number of researchers, but what is more difficult to determine are  the root cause of this decline, the reason for the lack of equality between school systems and the degree to which teachers can be held accountable.

(A) has been documented by a number of researchers, but what is more difficult to determine  are  - 'decline' is singular noun and so we need singular verb 'has'. 'root cause' is singular noun and so we need singular verb 'is'

(B)  has  been documented by a number of researchers, but what is more difficult to determine  is  - 'decline' is singular noun and so we need singular verb 'has'. 'root cause' is singular noun and so we need singular verb 'is'

(C)  have  been documented by a number of researchers, but what is more difficult to determine  are  - 'decline' is singular noun and so we need singular verb 'has'. 'root cause' is singular noun and so we need singular verb 'is'

(D) is documented by a number of researchers, but what has been more difficult to determine  are  - 'decline' is singular noun and so we need singular verb 'has'. 'root cause' is singular noun and so we need singular verb 'is'

(E)  are  documented by a number of researchers, but what is more difficult to determine is - 'decline' is singular noun and so we need singular verb 'has'. 'root cause' is singular noun and so we need singular verb 'is'

bibha · Answer

what is more difficult to determine are the root cause of this decline, the reason for the lack of equality between school systems and the degree to which teachers can be held accountable.

In this part of the sentence, i think "are" is better than "is" since there are three things that are most difficult to determine. Isn't it?

lagomez · Answer

The coordinating conjunction "but" creates another sentence, which is made of of an independent clause and a dependent clause. The subject and the verb must be in the independent clause.

What is more difficult to determine is the root cause of this decline - independent clause

the reason for the lack of equality between school systems and the degree to which teachers can be held accountable - this is a dependent clause hence the main subject and the main verb can not be in this sentence. This sentence modifies cause and does not act like a subject.

The decline in students' perfomances on state-wide tests

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