Official ExplanationAccording to recent research, eating a plant-based diet
not only reduces one’s risk to impair cognition but also lowers the risk of developing cancer.
A. not only reduces one’s risk to impair cognition but also lowers theB. not only reduces one’s risk of cognitive impairment but also lowers one’sC. reduces not only one’s risk of cognitive impairment but also lowers one’sD. reduces not only one’s risk to impair cognition but also lowers theE. reduces one’s risk not only of cognitive impairment but also lowers one’sAfter a quick glance over the options, we have a few key differences we can focus on to narrow down our choices:
1. not only reduces / reduces not only / reduces…not only (Idioms)
2. to impair cognition / of cognitive impairment (Parallelism & Meaning)
3. the / one’s (Parallelism)A quick look at the original sentence reveals a somewhat common idiom: not only X, but also Y. Let’s start there, and eliminate any options that don’t make X and Y parallel:
A.
not only reduces one’s risk to impair cognition
but also lowers the
B.
not only reduces one’s risk of cognitive impairment
but also lowers one’s
C. reduces
not only one’s risk of cognitive impairment
but also lowers one’s
D. reduces
not only one’s risk to impair cognition
but also lowers the
E. reduces one’s risk
not only of cognitive impairment
but also lowers one’s
We can eliminate options C, D, & E because they don’t follow a parallel formatting for the “not only X, but also Y” idiom structure. In options A & B, the X and Y are both present tense verbs, which is parallel.
Now that we have it narrowed down to only 2 options, let’s tackle #2 and #3 on our list. They both have to do with parallel structure and creating a clear meaning. To make problems easier to spot, let’s also add in the rest of the non-underlined ending:
A. not only reduces one’s risk to impair cognition but also lowers the risk of developing cancer.
This is
INCORRECT for a couple reasons. First, the two phrases aren’t parallel. The phrases “reduces
one’s risk” and “lowers
the risk” are almost there, but they need to use the same the/one’s in both. Second, the phrase “to impair cognition” doesn’t work here for two reasons. Again, it’s not parallel to say, “
to impair cognition” and “
of developing cancer.” Also, the phrase “to impair cognition” implies that the plant-based diet is impairing cognition on its own. Since a diet is not a living thing that can DO things, this doesn’t make sense.
B. not only reduces one’s risk of cognitive impairment but also lowers one’s risk of developing cancer.
This is
CORRECT! Both phrases are written using parallel structures, and the phrase “of cognitive impairment” makes a lot more sense here because it doesn’t suggest the diet DOES an action – reducing impairment is just a potential side effect of a PERSON eating a plant-based diet.
There you have it – option B is our winner! By focusing on an idiom that we see quite often on the GMAT, we were able to narrow down our options rather quickly, leaving us more time to attack more complex issues!
Don’t study for the GMAT. Train for it.