Geologists once thought that the molten rock known as lava

Don't you think as per the option , erupting is modifying the geologists.

Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

(A) was an underground remnant of Earth's earliest days, sporadically erupting
(B) had been an underground remnant of Earth's earliest days and sporadically erupted
(C) was an underground remnant of Earth's earliest days, which sporadically erupted
(D) would be an underground remnant of Earth's earliest days that sporadically erupted
(E) was an underground remnant of Earth's earliest days, having sporadically erupted

That works for me, except we want a concrete reason to get rid of C. I save "wordy" for a last resort! In this case, C offers us a noun modifier: "which sporadically erupted." Earth's earliest days didn't sporadically erupt, so C is incorrect.

Does the ‘which’ in C really refer to the earliest days? I wouldn’t think so because logically one doesn’t expect days to erupt. We might see that the relative pronoun is preceded by a whole noun phrase immediately before and therefore the pronoun refers to the entire noun phrase rather than just the noun it is touching. Looked that way, I feel the pronoun touch rule is not in debate in C

Proof for this treatment comes for the legendary official example of the Emily Dickinson’s letters to Susan Huntington Dickinson and the ample enlightenment of the issue by Ron in his observation in the link---
https://www.manhattanprep.com/gmat/foru ... t6529.html

A. was an underground remnant of Earth's earliest days, sporadically erupting

B. had been an underground remnant of Earth's earliest days and sporadically erupted

C. was an underground remnant of Earth's earliest days, which sporadically erupted

D. would be an underground remnant of Earth's earliest days that sporadically erupted

E. was an underground remnant of Earth's earliest days, having sporadically erupted

Verb+ing modifier should modify the preceding clause, and at the same time make sense with the subject of the preceding clause.

Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

(A) was an underground remnant of Earth's earliest days, sporadically erupting
(B) had been an underground remnant of Earth's earliest days and sporadically erupted
(C) was an underground remnant of Earth's earliest days, which sporadically erupted
(D) would be an underground remnant of Earth's earliest days that sporadically erupted
(E) was an underground remnant of Earth's earliest days, having sporadically erupted

Anud wrote
I am extraordinarily confused now with two things - 1. About how different people suggest different things regarding the suitability of using a verb+ing modifier and 2. Exception to the noun modifier rule.

I would really appreciate it if anybody could help declutter my thought process. I am delineating the same here (Was that an oxymoron? :P ):

1. Using the tense logic, I was able to eliminate B & D.
2. Eliminate E: having sporadically erupted -> The participial phrase, I thought, was modifying the geologists.

Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes .. In the question stem, "that begins a relative clause" and the verb+ing modifier comes after the clause also containing the independent clause - Geologists once thought.

having sporadically erupted is a participial phrase and a participial phrase always requires a subject. Isn't this modifying geologists? Either way, even if it referred to the molten rock, the tense is still off. having sporadically erupted makes it seem as if it was a one-off activity which happened in the past.

3. Next, between A & C:

As mikemcgarry mentioned, I have seen a few instances where of something typically functions as a vital noun modifier and is followed by a which clause. So, I didn't rule it out because of the incorrect modifier touch rule.
With A, again, I got super-confused because it was a verb+ing modifier. I am quoting e-gmat here: ->

Verb+ing modifier should modify the preceding clause, and at the same time make sense with the subject of the preceding clause.

And according to me, having sporadically erupted didn't make sense with geologists. Which is why I picked C.

I would really appreciate it if somebody could please provide the right use-case for a verb+ing modifier and explain why it is correctly or incorrectly referring to molten rock here? Getting this concept straight will go a long way in getting modifier questions correct.

mikemcgarry, AjiteshArun, daagh, DmitryFarber, GMATNinja. Please help.

That works for me, except we want a concrete reason to get rid of C. I save "wordy" for a last resort! In this case, C offers us a noun modifier: "which sporadically erupted." Earth's earliest days didn't sporadically erupt, so C is incorrect.

Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.


A. was an underground remnant of Earth's earliest days, sporadically erupting

B. had been an underground remnant of Earth's earliest days and sporadically erupted

C. was an underground remnant of Earth's earliest days, which sporadically erupted

D. would be an underground remnant of Earth's earliest days that sporadically erupted

E. was an underground remnant of Earth's earliest days, having sporadically erupted

We are retiring this problem in its current form, because it has several issues.

First, as you point out, "which" is not necessarily wrong here.

Second -- and more importantly -- the ostensibly correct answer to this problem doesn't actually work.
In choice A, the modifier "sporadically erupting..." does not describe anything in the preceding part, so it doesn't make sense as a "comma + __ing" modifier (which must meaningfully describe the subject+action of the preceding sentence).
Incidentally, choice A of the Dickinson problem (OG12 #26) is wrong for exactly the same reason!

This problem is no longer in our database. It will be replaced by an updated (and fully correct) version soon.

Because the problem is no longer in the database, this thread is now retired.

Thanks.