Good question. +1 kudo.

A supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, and which can make the moon appear much larger and brighter than the moon typically does.

supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, and which can make the moon appear
Wrong. Meaning problem. See red part, a supermoon makes the moon larger and brighter. Does it make sense? Not at all, a supermoon is still a moon itself, but appears larger because of its abnormal movement (closest to approach the Earth).

supermoon is the full or new moon that occurs when the moon is at or near its closest approach to the Earth and can make the moon appear
Wrong. Meaning problem. See red part, a supermoon CAN'T make the moon larger and brighter because the supermoon is the moon itself. Same error as in A.

supermoon is the full or new moon that occurs when the moon is at or near its closest approach to the Earth and appears
Correct. See blue part: a new moon appears much larger and brighter..... => Make the most sense.

supermoon is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, a position which causes itself to appear
Wrong. "A position" CAN'T make itself larger and brighter. It makes no sense.

supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, causes the moon to appear
Wrong. Meaning problem. See red part, a supermoon CAN'T cause the moon larger and brighter because the supermoon is the moon itself. Same error as in A.

Hope it helps.
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A supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, and which can make the moon appear much larger and brighter than the moon typically does.

Meaning:
Supermoon is a full or new moon that occurs when the moon is at or near the Earth and this can make the moon appear much larger and brighter than usual.

Sentence analysis:
(1) Supermoon is the main subject but it does not have a verb.
(2) 'Which' correctly adds more information about supermoon and 'which' has a verb 'is' (both are singular).
(3) 'that' (refers to moon) is the subject of the third clause and its verb is 'occurs'.
(4) 'and which can make....' is incorrectly referring to supermoon but in the correct version it means to say that when the moon is at or near its closest approach to the earth, it appears larger and brighter.


Option C corrects all these errors.
Supermoon is the full or new moon
that occurs
when the moon is at or near its closest approach to the Earth and appears much larger and brighter than the moon typically does.

'is' and 'appears' are the two verbs of 'moon'.


This is what I have understood. Please correct me if I the analysis is wrong. Also can anyone explain the role of 'does' here? Is 'does' a verb here?
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"Did" and "does" aren't actually pronouns -- in this case, "does" functions sort of like a pronoun, but for verbs. But it definitely isn't a pronoun -- it can just be used to avoid repeating the same verb twice in a sentence:

Shiv2016 studies much more than Carcass studies. --> sounds kind of silly and redundant, right?
Shiv2016 studies much more than Carcass does. --> "does" refers back to "studies", and avoids repetition

So in the original question:

"the supermoon... appears larger... than the moon typically appears" --> this would sound silly and redundant, right?
"the supermoon... appears larger... than the moon typically does" --> much better, yes? Which is why it's in the correct answer choice.

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A supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, and which can make the moon appear much larger and brighter than the moon typically does.

(A) supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, and which can make the moon appear

(B) supermoon is the full or new moon that occurs when the moon is at or near its closest approach to the Earth and can make the moon appear

(C) supermoon is the full or new moon that occurs when the moon is at or near its closest approach to the Earth and appears correct

(D) supermoon is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, a position which causes itself to appear

(E) supermoon, which is the full or new moon that occurs when the moon is at or near its closest approach to the Earth, causes the moon to appear

VERITAS PREP OFFICIAL EXPLANATION:

(A) contains a sentence construction error: the subject "supermoon" never gets a verb, so we are left with a fragment.

(B) suggests either that "a supermoon" can make the moon appear larger or that "the moon" can make the moon appear larger, but neither of these construals is acceptable, since a supermoon is the moon and one would never say that "the moon makes the moon appear larger."

(C) correctly suggests either that "a supermoon" appears much larger than the moon typically does or that "the moon" appears much larger than the moon typically does.

In (D), the phrase "causes itself" does not work logically, since the position does not make itself appear larger.

(E) suggests that the "supermoon" causes the moon to appear larger, but that claim is illogical, since the "supermoon" is the moon.

Note: (B) and (C) are both characterized by the same flexible/fuzzy subject-verb relationships. In (B), either "a supermoon" or "the moon" (first instance) could be legitimately posited as the subject of "can make"; in (C), either "a supermoon" or "the moon" (first instance) could be legitimately posited as the subject of "appears." What's important is that whichever construct one favors, the reasoning above holds: (B) doesn't work and (C) does.
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