think of x as y is correct idiom. Also in this sentence not x but y parallelism is employed.

A.not an .. is not parallel to but as
B. not expense but as -- not parallel
C. think of x as required
D. correct
E. same as c, in terms of is wrong.

With babuvgmat

Answer will be (D)

In her presentation, the head of the Better Business Bureau emphasized that companies should think of the cost of conventions and other similar gatherings not as an expense ,but as an investment in networking that will pay dividends.

In her presentation, the head of the Better Business Bureau emphasized that companies should think of the cost of conventions and other similar gatherings not as an expense ,but as an investment in networking that will pay dividends.
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Correct Idiom: Not X but Y
Where X must be parallel to Y.

A-- Not (an expense) but (as) -- Not parallel
B-- Not (expense) but an investment -- Not parallel
C-- Not (an expense), rather -- Correct idiom is Not X, but rather Y
D-- Not (as an expense), but (as an expense) -- Parallel
E-- Not (in terms of expense), but (an investment) -- Not parallel

D
parallelism of 'not as... but as...'

New OG 2017 questions are easy!

In her presentation, the head of the Better Business Bureau emphasized that companies should think of the cost of conventions and other similar gatherings as not an expense, but as an investment in networking that will pay dividends.

A) as not an expense, but as
B) as not expense, but
C) not an expense, rather
D) not as an expense, but as
E) not in terms of expense, but

Of course, happy to help and flex the grammar muscles a bit.

A) not bad. However, it's not perfect, because of the incorrect order of the words "as" and "not". For example, there is a reason why we say "not bad", and not, "bad not". The "not" is the more important word in this sentence and thus should come first, for clarity.
B) missing the 2nd "as" (in addition to the "an")
C) the mystery of the disappearing "as"s
D) correct
E) same as C

The first "as" is there, but the second "as" is not. The correct expression is "not as A, but as B." Thus, two "as"s are necessary. In addition, one does not think of something "as expense"--one thinks of something "as an expense", since "expense" is a noun and not an adjective / adverb, and thus requires "a" or "an" (indefinite article).

For example:

I think of him warmly (adverb) = correct
I find him annoying (adjective) = correct
I think of it as expensive (adjective) = correct
I think of it as expense (noun) = incorrect
I think of it as an expense (noun) = correct

The reason why you need two "as"s is idiomatic--it's just the way the expression works, and it creates parallel structure. Since there are two ways to think of something, there should be two "as"s.

I think of you not as a co-worker, but a friend. = incorrect
I think of you not as a co-worker, but as a friend. = correct

The same holds true for prepositions in general, when used in a similar way.

I am going not to Yale, but Harvard. = incorrect
I am going not to Yale, but to Harvard. = correct

Let's discuss it more generally, in terms of templates, and then again with specific examples:

"Subject + Verb/Predicate + Preposition + Any Objects of the Preposition" = correct (you don't have to repeat the preposition for additional objects)

For Example: "I like to go to the beach and the mountains." (Don't have to repeat "to" because the "to" is already established as the preposition of that verb.)

However,

"Subject + Verb/Predicate + Preposition + comma + BUT + no preposition..." is less correct, though people do so all the time in everyday speech. The reason why is that a punctuation/word such as ", but" serves as a possible "pivot point" in the sentence and thus requires a new preposition to confirm that the second clause is modifying the first, and not moving on to a whole other thought.

Ex: "I think of you not as an enemy, but a friend of mine is coming over soon and I need to clean the living room." I know this is a silly example and few would interpret it this way, but that's how grammar works. Any possible misinterpretation, no matter how illogical or unlikely, is the enemy of correct grammar.

Otherwise it sounds like you could possibly talking about a different friend, not extending your original thought. I know it's complicated, but it's possibly to simply memorize the rule rather than try to make sense of it, as I am doing. Sometimes the most important aspect of English grammar is understanding the importance of idioms: "that's just how you say it." That being said, this particular rule does have some logic behind it.

IN SUM:

"I think of you not as an enemy, but a friend" = incorrect but accepted
"I think of you not as an enemy, but as a friend" = better for clarity[/size]

In her presentation, the head of the Better Business Bureau emphasized that companies should think of the cost of conventions and other similar gatherings as not an expense, but as an investment in networking that will pay dividends.

A) as not an expense,but as
B) as not expense,but
C) not an expense,rather
D) not as an expense,but as
E) not in terms of expense,but

Vertical Scan reveals that Option A, B, and D have 'as' and option C and E do not have 'as'
The sentence has 'think of the cost.........gatherings'
The correct use is 'think of X as Y'
Therefore, C and E are out

A, B and D have a pair 'not....but....'

This pair demands a parallel construction
A: not an ...,but as not paralle....Out
B: not expense ,but an not parallel...Out

Therefore D (not as ....,but as...)
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In Option D,here there is no subject after but.
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In her presentation, the head of the Better Business Bureau emphasized that companies should think of the cost of conventions and other similar gatherings as not an expense, but as an investment in networking that will pay dividends.

A) as not an expense,but as - idiom issue - “think of X not as Y but as Z”
B) as not expense,but - idiom issue
C) not an expense,rather - “Not…rather” is non-idiomatic
D) not as an expense,but as - Correct
E) not in terms of expense,but - parallelism issue - “in terms of expense” and “an investment”

Answer D
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