According to a study by a prominent think tank, the defense budget of

OA from Kaplan is below. Interesting, I guess I learn about GMAC's preference.

"Read the Original Sentence Carefully, Looking for Errors:

Official GMAC review materials have stated, "To establish numerical comparability between groups with countable members, the phrase 'as many as' is preferable" to phrases such as "equivalent to" and "equal to." What this means is that for countable nouns such as dollars, flowers, and socks, you should use "as many as." For example, "There are as many weeds as flowers in this garden" is preferable to "The flowers are equivalent to the weeds." For uncountable nouns such water, force, and soup, it's correct to say either "as much" or "equal to." For example, it's correct to say "an amount of water equal to Lake Ontario" or "an equivalent amount of force."

In this question, the goal is to say that the "70 billion dollars" is the same as what the private grants are donating. Dollars are countable nouns, so it's not accurate by GMAT standards to use a phrase like "equivalent to."

The other issue you may have spotted in this sentence is that it makes a faulty comparison between the "70 billion dollars" and "private grants." Comparisons on the GMAT must be fair and parallel, and it isn't accurate to compare money to grants – the idea is to compare the money to the money the grants provide.

Scan and Group the Answer Choices:

Choices (A) and (B) begin "equivalent to," choice (C) begins "equal to," (D) begins with "as much as," and (E) begins with "as many as." Another useful split is between choices (A) and (D) which end "private grants" and choices (B), C), and (E) which introduce the verb "provide."

Eliminate Wrong Answer Choices:

As stated earlier, phrases such as "equivalent to" or "equal to" are less preferable than phrases like “as many as” or “as much as,” so eliminate choices (A), (B), and (C). Choice (B) is also unnecessarily wordy, employing the passive voice.

The difference between choices (D) and (E) is the word "provide." As discussed above, we'd have to use the word provide here to complete the comparison. Because "provide" is necessary, choice (D) is incorrect.

If we put Choice (E) back into the original sentence, the new sentence would read, in part: "The defense budget might… fund more than 70 billion dollars annually…, as many as private grants provide." All the pieces match up perfectly, so Answer Choice (E) is the correct answer."