nechets
This question is basically trying to measure your capacity to read for meaning in parallel structures. However, I suspect that the correct answer choice (E) does poorly its intent, because GMAT is very strict in terms of "which" usage. "Which" should only refer to previous term.
Read for meaning: The sentence wants to compare new varieties of antibiotics with earlier varieties. Pay attention to where the term "earlier high-strengh varieties" is located in the sentence. Any choice that refers only to one aspect of "earlier high-strengh varieties", you can eliminate it. Go ahead and cross these answers out:
New, strong varieties of antibiotics show the potential to kill a harmful bacterium without the
unintended effects of killing benign bacteria and development of resistant strains of bacteria by earlier high-strength varieties.
a. unintended effects of killing benign bacteria and
the development of resistant strains of bacteria by earlier high-strength varieties - linked only to the 2nd aspect b.
unintended effects by earlier high-strength varieties of development of resistant strains and killing benign bacteria
- linked only to the 1st aspectc. unintended effects for the development of resistant strains of bacteria and
killing benign bacteria of earlier high-strength varieties - linked only to the 2nd aspectd. development of resistant strains of bacteria and
killing of benign bacteria that were required by earlier high-strength varieties - linked only to the 2nd aspect, no comma, no distributione. killing of benign bacteria and development of resistant strains of bacteria, which were unintended effects of earlier high-strength varieties
- close enough to refer to both terms, but notice that "which" actually refers to a term used in the beginning of the phrase "new, strong varieties of antibiotics" First off, thank you for sharing your thought process. I do have one correction though with (E).
e.
killing of benign bacteria and
development of
resistant strains of bacteria,
which were unintended effects of earlier high-strength varieties
"which" as we know follows the touch rule. There are however exceptions to this where it can go back to refer to earlier mentioned nouns, PROVIDED that there is NO VERB between that particular referent noun and the "which". This is where your explanation of "which" referring to the beginning of the phrase "new, strong varieties of antibiotics" is incorrect.
If we look at the structure, "which" is followed by the plural verb "were" and the only valid plural noun is "resistant strains". Approaching this from a meaning clarity perspective - usually when high strength antibiotics are prescribed to patients, it causes some bacteria to develop resistance making these bacteria more resilient to that particular antibiotic. This effect medically is generally "unintended". You don't need to be making bacteria strong with medicine.
I would also like to give an alternate usage of "which" - it may be referring to "killing" and "development" together since "were" is used as a verb. Killing benign bacteria (which are basically harmless bacteria) could also be an "unintended effect" because the main purpose of any antibiotic is to attack the harmful bacteria only.
Either way (E) will be the CORRECT choice because of the restrictive usage of "that" in (D) that causes the meaning to be altered dramatically. Refer this link for the restrictive nature of "that"
https://gmatclub.com/blog/2012/04/that-vs-which-in-gmat-sentence-correction/
24 Jan 2021, 21:52
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