Each of the vegetables in the store had been washed with

Official Answer:

There are two main issues in this sentence, pronoun and verb tense. I will choose to work with verb tense as the first issue. In this case, one thing happened before another in the past and therefore the first event requires the use of past perfect while the second event requires simple past. There are some cases, in which specific time is mentioned in which past perfect is optional but this is not such a case because the event happened at an undetermined time in the past. Therefore past perfect is required and B, C and E are eliminated.

The second issue is pronoun. Answer D uses "it" while Answer A uses "they". most people think the subject of the sentence is vegetables but the subject of a sentence cannot be in a prepositional phrase. Therefore, the subject of the sentence is Each, which is a singular pronoun thus the correct pronoun is "it" and the answer is D.

'D' stands out as the most logical answer here ....Use of past perfect is very much needed ...Other difference being use of 'it' as Each of needs a singular pronoun...

Now as Zarrolou has pointed out that its not necessary to use past perfect if the sequence of the actions has been clearly demarcated using "BEFORE" ...As far as grammar says ... If the Past Perfect action did occur at a specific time, the Simple Past can be used instead of the Past Perfect when "before" or "after" is used in the sentence. The words "before" and "after" actually tell you what happens first, so the Past Perfect is optional. For this reason, both sentences below are correct.
Examples:

She had visited her Japanese relatives once in 1993 before she moved in with them in 1996.
She visited her Japanese relatives once in 1993 before she moved in with them in 1996.

On the other hand..

If the Past Perfect is not referring to an action at a specific time, Past Perfect is not optional. Compare the examples below. Here Past Perfect is referring to a general action rather than an action at a specific time. For this reason, Simple Past cannot be used.
Examples:

She never saw a bear before she moved to Alaska. Not Correct
She had never seen a bear before she moved to Alaska. Correct

A incorrect because past perfect is not needed as before correct define the sequence

B is correct

C They is incorrect , each of the vegetables is singular subject

D same A

E awkward

As per the meaning and sequencing of events The vegetables were washed and then they were sold.

Only A and D have the right tense. Since "each" is singular you need "it"

So A is incorrect because of "they" Hence Answer is D

I want to know if it is a questions from GMAC.

Also i want to know if the past perfect tense is actually required here since use of "before" already denotes the time sequence correctly. I want further discussion on this.

Past perfect is not required when sequence of events is evident with the use of words like Before and After.
In this case before clearly states that vegetables were washed before selling.

Please let me know if my information on this subject is incorrect.

above idea is correct.

this question is wrong. both choice b and d are correct.

I don't agree with you. I think that 'before' is obvious signal that we must use 'had' to indicate 1 action occurred before another one. If its possible cite the source for such a strict rule that you said. thanks

i think option b is correct as the use of the word "before" clearly states that the veggies were washed before selling...could someone please elaborate and explain why we cannot omit the use of past perfect tense.

Thanks

In fact you can go either way. B and D are both fine.

If the order of the events is clear "X before Y" the past perfect is not required (I cannot say it's wrong, but it's unnecessary).
There is no much evidence to choose between B and D, so if you pick B you are fine.

Really nice explanation. Except for I did not understand past perfect and everything. Anyways I looked up.

So this is 2015, and from what I have gathered, B is grammatically correct (and actually preferred over D, as it is suggested in MGMAT SC Guide to stay away from perfect tenses unless they are necessary). The time indicator "before" makes the usage of past perfect unnecessary, regardless of exactly when the washing happened.
But you are an expert who has stated otherwise, and I'm really interested in knowing if B can still be considered incorrect. Any opinions?

had been is needed because there was an activity that happened in the past before another action that happened in the past. Also, it is required at the end because each is the subject and of the vegetables is the prep phrase.

Can you please explain how do we determine the 'undetermined' and 'undetermined' time? After reading the above example my first thought was that we don't need a past perfect tense to express the meaning of the sentence effectively. Your help will be appreciated.

Thanks.

I also selected B . Not sure why D is the answer . There is obvious sequence in the two action . Can any expert help. Thanks

I read through all the solutions presented here, but I still don't exactly understand why the presence of 'before' in B does not preclude the use of past perfect here.

Can someone please explain this!

Still, I don't understand why 'D' is OA when the question clearly mentions 'Before". Ruled out 'D' just because the usage of Past perfect tense is not necessary.
Chose 'B'.

Looking forward to an expert to give an explanation.

Hi

Let me try to address your query.

A past perfect tense is used when there are two events occurring in the past, to refer to the earlier of those two events. Let us plug in answer option (B) into the sentence and examine it:

Each of the vegetables in the store was washed with vegetable wash before it was sold.

As we can clearly see, there are two events happening in the past tense:

Earlier event: washed with vegetable wash
Later event: was sold

We need to use the past perfect tense to refer to the earlier event. Hence, "washed with vegetable wash" needs to be preceded by "had been".

Hope this clarifies.
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Not satisfied with your explanation since in Aristotle, it is clearly mentioned that if phrases like "before"/previously etc. is explicitly mentioned in the sentence then there is no need to use a past perfect. However, we can still use a past perfect if we want to