Hello Everyone!
This looks like a great example of a GMAT question that focuses on parallel structure! Let's go through each option carefully to narrow them down to the right answer! To get started, here is the original question:
Positing an enormous volcanic explosion at the end of the Permian period would explain the presence of a buried crater,
account for the presence of the element iridium (originating deep within the earth), and the presence of quartz having been shattered by high-impact shock waves.
(A) account for the presence of the element iridium (originating deep within the earth), and the presence of quartz having been
(B) of the element iridium (originating deep within the earth), and of quartz
(C) the element iridium (originating deep within the earth), and explain the presence of quartz having been
(D) the presence of the element iridium (originating deep within the earth), and explain the presence of quartz
(E) explain the element iridium (originating deep within the earth), and the presence of quartz
One important sign that we're dealing with parallelism is when the options are part of a list. Any time you see a list, it's a good idea to start by asking yourself, "Is each item in the list worded/structured similarly?" Let's take a closer look at each option to throw out any answers that aren't parallel. To make it easier to spot, I've included the non-underlined part of the list because everything MUST match that in structure, verb tense, and tone:
(A) would
explain the presence of a buried crater,
account for the presence of the element iridium (originating deep within the earth),
and
the presence of quartz having been
This option is
NOT PARALLEL because each item in the list is introduced using a different verb, or none at all: explain / account for / no verb. Therefore, this is
INCORRECT because it's not parallel.
(B) would explain the presence
of a buried crater,
of the element iridium (originating deep within the earth),
and
of quartzThis option is
PARALLEL because each item is introduced in a similar manner (using the word "of"). It's much simpler and more concise, too! Therefore, this is the
CORRECT option because it uses parallel structure.
(C) would
explain the presence of a buried crater,
the element iridium (originating deep within the earth),
and
explain the presence of quartz having been
This option is
NOT PARALLEL because only 2 out of 3 items starts with "explain the presence of." For this to be parallel, all 3 items need to match. Therefore, this is another
INCORRECT option!
(D) would
explain the presence of a buried crater,
the presence of the element iridium (originating deep within the earth),
and
explain the presence of quartz
This option is also
NOT PARALLEL because it only uses the verb "explain" in 2 of 3 items in the list. They're very close to parallel, but not quite good enough! Therefore, this option is
INCORRECT because it doesn't use parallel structure.
(E) would
explain the presence of a buried crater,
explain the element iridium (originating deep within the earth),
and
the presence of quartz
This option is
NOT PARALLEL because each item uses different combinations of the phrases "explain the presence of," "explain," and "the presence of." For this to be parallel, all 3 items need to match. Therefore, this option is
INCORRECT because it doesn't use parallel structure.
There you go - option B is the correct answer because it's the only one that uses parallel structure!Don't study for the GMAT. Train for it.
_________________
EMPOWERgmat
Total GMAT Content & Tactical Training | 120 Point Guarantee | All 6 Official GMAT Tests
empowergmat.com