The management was impressed by the fact that even though John had

[OFFICIAL EXPLANATION



HIGHLIGHTS

• We need contrast. How do we know that fact?

We do not need contrast because A shows contrast,
We need contrast because one word, two phrases, and a word in three options indicate contrast.

One word, impressed, indicates something unusual. Two phrases comprehensive report and concise manner, suggest two things that do not usually go together.
-- the managers were impressed [people are impressed when they get better than they expect, so start looking for words and phrases that indicate something surprising or unexpected]
and
-- two phrases indicate things that do not usually coincide: a comprehensive report and [delivered in a] concise manner[/i]

The managers are impressed because John wrote some humongous report but delivered it succinctly.
Now they can go drink martinis earlier than usual.

Suppose that A lacked contrast. We would still be looking for contrast.
We take the "intended meaning" from cue words in the prompt (impressed) and from options (comprehensive and concise, in different forms, are in all options, and a contrast word is in three)

• Verb tense

PAST PERFECT
Yet again we contend with past perfect.
When two events happen in the past and one comes before the other,
the earlier event takes past perfect the later event takes simple past

Is the usage of past perfect okay?

Construction
Construction of past perfect, ACTIVE voice:
HAD + past participle (verbED)

Construction of past perfect, PASSIVE voice:
HAD + been + past participle (verbED)

Requirements
Past perfect, often called the past of the past requires
-- at least one event rendered in simple past tense OR a time marker such as BY 1945
and
-- usually not any sequence words.
The verb tense itself announces to English readers and speakers that one event preceded the other.

We have two simple past tense verbs: was impressed, and presented.
presented is probably more important than "was impressed," but either simple past tense will work.
-- Don't forget that was impressed is simple past tense.
In the meeting in which the management was impressed [simple past], John presented [simple past] the report that he HAD prepared [past perfect]. That logic works.

SIMPLE PAST?
Tough call.
If we have two nearly identical or identical sentences in which one event precedes another and both are in the past,
and we have to choose between simple past or past perfect,
we should look for another decision point.

When we use simple past tense as in B, often a sequence word will be included. (In that case, if sequence is clear, the sentence is perfectly acceptable.)
If the verbs logically go in a certain order, though—you cannot present something that you have not yet prepared—or if sequence is clear for some other reason (dates, for example), we should not reject simple past tense automatically.

• COMMA + ___ING in option D? It's okay.
comma + present participle can modify the previous clause; modify the subject of the previous clause; modify the immediately preceding noun (see the official Holland Tunnel question); and talk about simultaneous or nearly simultaneous events that are logically related.
The present participle modifier can do more than those things, too, though the list I just wrote is what you will see on the test.

THE OPTIONS
• grammatical but a little weird. GMAC does not like a shift from active voice to passive voice (or vice versa) in the same sentence.
• grammar and meaning are okay, KEEP for a bit

• although and yet are redundant and cancel each other out

• everything is correct and unlike A, this option does not shift from active to passive voice

• no contrast word exists
• the good news: past perfect plus "a very comprehensive report" keep our focus on sequence, and "presenting" and "concise" are in a different part of the sentence.
• is the management impressed because John did his job? Doubtful.
You don't get a Bozo button for doing the right thing. (That is vintage yours truly.)
• most importantly, is this option as good as C? NO

• this sentence is grammatical and well-written
• now it really sounds as if the management was impressed because John did his job well because he HAD prepared and HAD delivered . . .
but it does not sound as if the management's admiration stems from John's ability to deliver a long report quickly
• most importantly, is this option as good as C? NO.

Now compare A and C. No contest. C says exactly what (A) does without switching voices.

The answer is C

COMMENTS

I am glad to see all of you.
I underlined good in "good" explanations because to explain why the answer is C requires
(1) that posters say what is wrong with an option and why , and
(2) that posters explain why all four options get eliminated—not just one or two options.

[Keep in mind that you are writing for future readers. Can someone come to this thread, read your answer, and understand? Pretend that person has not done 200 hours' of studying. Anyone know why I put a possessive marker on the end of "hours"?)

Kudos go to those who explained fully—and if I think that the reasoning is coherent even though it led to the wrong conclusion (wrong answer), I will give those posts kudos too.
I promise, knowing how we might go wrong is as important as knowing how to get it right.
Smiley faces go to partial answers with explanations.
No explanation = no smiley face and no kudos (not applicable here).

I respect the effort I see. Nice work.