Hello Everyone!

Let's tackle this question, one problem at a time, and figure out how to get to the correct option quickly! To start, here is the original question with any major differences between the options highlighted in orange:

The Organization of Petroleum Exporting Countries (OPEC) had long been expected to announce a reduction in output to bolster sagging oil prices, but officials of the organization just recently announced that the group will pare daily production by 1.5 million barrels by the beginning of next year, but only if non-OPEC nations, including Norway, Mexico, and Russia, were to trim output by a total of 500,000 barrels a day.

(A) year, but only if non-OPEC nations, including Norway, Mexico, and Russia, were to trim output
(B) year, but only if the output of non-OPEC nations, which includes Norway, Mexico, and Russia, is trimmed
(C) year only if the output of non-OPEC nations, including Norway, Mexico, and Russia, would be trimmed
(D) year only if non-OPEC nations, which includes Norway, Mexico, and Russia, were trimming output
(E) year only if non-OPEC nations, including Norway, Mexico, and Russia, trim output

After a quick glance over the options, a few key differences jump out:

1. only if vs. but only if
2. including vs. which includes
3. were to trim / is trimmed / would be trimmed / were trimming / trim

Let's start with #1 on our list: only if vs. but only if.

The words "but" and "only if" both seem to have the same function here - to create a conditional statement. We also have the conjunction "but" used earlier in the sentence. It's generally considered a bad idea to use the same coordinating conjunction (and, for, nor, but, or, yet, so) more than once in a sentence. So let's rule out A & B because they repeat the conjunction "but," which makes this sentence sound redundant and confusing.

Next, let's tackle #3 on our list: verb tense of "to trim." We need to make sure that whichever option we choose uses active voice, the correct verb tense, and conveys a clear meaning to the reader. To more easily spot the problem here, I'm going to cross out the non-essential phrase that's meant to throw you off:

(C) year only if the output of non-OPEC nations, including Norway, Mexico, and Russia, would be trimmed

This is INCORRECT because it distorts the meaning. By saying "would be trimmed," it suggests that some other person/group will trim output - not the nations themselves, which is the intended meaning.

(D) year only if non-OPEC nations, which includes Norway, Mexico, and Russia, were trimming output

This is INCORRECT because it uses past tense instead of present or future tense. The non-OPEC nations haven't started trimming output already - otherwise this wouldn't be a problem. The condition is that OPEC will reduce their production in the future if those nations trim their output from here on out. The verb tense used here doesn't make logical sense, so it's wrong.

(E) year only if non-OPEC nations, including Norway, Mexico, and Russia, trim output

This is CORRECT! Using the present tense "trim" works here because the non-OPEC nations have to start trimming output now, so that OPEC will do what they say they're going to in the future.

There you have it - option E is the best choice!


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