Geologists once thought that the molten rock known as lava

brandy96,
I am with you . According to Ron's explanation
when you have "X of Y" before a modifier of this type, the modifier could potentially refer either to "Y" by itself or to the whole unit "X of Y". It's up to context to determine which.
https://www.manhattangmat.com/forums/post5311.html#p5311

So here which can refer back to underground remnant ...However MGMT says OA IS

There is no problem. "ing" modifier modifier the previous clause.

C is wrong because of which. which is touching "days" when it should be modifying "lava"

Thanks for your reply..
I believe by saying "ing" modifier modifies the previous clause. you mean to say its an adverbial modifier and should modify the main verb of the previous clause and should provide answer to why, how and when questions?

Now Lets consider the first part of the sentence

[strike]Geologists once thought that[/strike] the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes.

Ask yourself.

why was lava an underground remnant of Earth's earliest days ?.....
Answer : coz it sporadically erupted through volcanoes :....Answer is nonsensical

How was lava an underground remnant of Earth's earliest days ?....
Answer : It sporadically erupted through volcanoes ...this too is awkward..

When was lava an underground remnant of Earth's earliest days ?....definitely no answer

Regarding C Please have a look at Ron's explanation (for usage of which)@https://www.manhattangmat.com/forums/post5311.html#p5311

Am I missing something?

A it is.I got it by POE. We need a simple past tense here. So B and D are out.In C, the use of which indicated that 'earliest days' erupted. Similar in E. So A wins

gmat1220 ,
I am still confused,
Which can refer back to preceding noun or a noun phrase .

So an underground remnant of Earth's earliest days is a noun phrase here and which can refer back to an underground remnant of Earth's earliest days .

I am just curious to know why we need modifier that modifies a entire preceding clause here?


COMMA + -ING modifier modifiers refer to the subject and action of the preceding clause, and imply a very specific relationship between the modifier and the action in that clause: the -ING action must be either
(1) simultaneous with AND subordinate to, or
(2) a direct and inevitable consequence of, [/i]

I dont think sporadically erupting through volcanoes is either a simultaneous or an inevitable consequence of the preceding clause? Can you please help me to understand .

Ron’s stand has been equivocal. His pronouncement is that . Here the whole unit of X of Y is a noun phrase and not a clause. Stacey is more categorical on this. Stacey wrote:

A relative pronoun ‘which’ can go only that far as a preceding phrase. But a participial modifier (the verb=ing form) can go much farther, modifying the entire previous clues. In
The given case, the author intends to refer the modifier, ‘sporadically erupting’ to the entire clause saying that the molten rock known as lava was an underground remnant of Earth's earliest days. ...
Finally, why did MGMAT choose A as OA, outweighing Ron’s thesis? (Although both are from the same stable). I think it is because of the wonderful utility of a participial modifier such as verb+ing, which can be pulled as long as required.

I will impulsively ignore C and be happy with A.

I agree with daagh's interpretation. Stacey explanation makes more sense to me. Although Ron has a point I will weigh it depending on the sentence. I always suspect which after the comma.

Posted from my mobile device

This question seems to have opened the pandora's box

To sum it all up!!

EXCEPTION TO COMMA + WHICH RULE
Which, who, where - are noun modifiers - and noun modifiers, by definition, have to touch the noun they modify

The best approach here is to think of "which" as a special modifier that attaches even more strongly to the noun than other modifiers. As a result, unlike most modifiers, "which” isn’t as easy to separate from its noun by an intervening modifier? In ALMOST ALL cases, you are safe to eliminate any answer where the "which" doesn't refer to the word immediately preceding it regardless of whatever else is going on.

Exception. . .
when nouns that are modified by prepositional phrases (Preposition = of, above) ---> If, in “X preposition Y” construction ,”Y” can GRAMMATICALLY be the referent of “, which” then pick Y, else pick “X” (noun) or “X preposition Y” (noun phrase)

Examples . . .
1) The picture of my brothers, which was taken last year in Mexico, is one of my favorites
- Which cannot refer to brother, because brother needs “who”, so which can only refer to Picture in this case.

2) The picture above my fireplace, which was taken last year in Mexico , is my favorite
- Fireplace could not have been taken

3) Emily Dickinson’s letters to Susan Huntington Dickinson, which were written . . .

Pictorially speaking. . .
See attached image. . .

Summary. . .
- DO NOT extend this pattern to prepositional phrases in which the object-of-preposition COULD ACTUALLY BE the antecedent of "which” i.e. in “X preposition Y”, Y could be antecedent of “which”
- Also, comma + which refers noun immediately preceding it or at best can refer to "noun phrase" represented by “X preposition Y”. But it can never refer back to "whole clause" . . .

Damn. . . this crazy!!

Target760

Target760 if you ever write a book I will read it thanks...,

Posted from my mobile device

Thanks daagh. Good Summarization! With all the above discussion now I am more clear on ", which" versus "-ing"

thanks!!

have added a pictoral representation too! just being creative

caio!