Video Explanation

Text Explanation

This question is very tricky, since two answer choices maintain parallelism,(B) and (C), yet the one that is stylistically inferior, (C), is the one that is actually correct. How can this be?

There are two main reasons:

Idiom error: “Ability for” is incorrect. The correct idiom should be “ability to”, not

Illogical Modification: In the last clause of the underlined part in (B), it says “our smartphones impair our working memory.” Smartphones are the subject of this clause, so when we continue on to the non-underlined part, “when doing something as fundamental as recalling”, we end up creating an absurd meaning: smartphones—not our memories—recall a string of digits. From the original sentence it is clear that it is our memories that recall the digits, not the smartphones. This error also happens in (D).

(A) “is impaired” is not parallel to “eroding” and “driving”. Watch out for the word “working”. It is not being used as a participle the way that “eroding” and “driving” are. It is part of the noun phrase “working memory”.

(B) See above.

(C) The answer. See above.

(D) makes several errors. First off, we want the three clauses following the colon to be parallel. “Is eroded” is not parallel to “driving” and “impairing”. The next error is the one described in “Illogical Modification” at the beginning of this explanation.

(E) “the conceptualization of space is eroded” creates a strange meaning by saying that space itself is being eroded, not that devices are eroding our ability to conceptualize space. “Distraction is driven by” and “working memory impairment is resulting from” or both awkward and the GMAT would always favor more concise phrasing, e.g., “working memory is impaired”.