option d says continents split apart which is correct but as u say continents to split apart is not there in the options

What is wrong with option B here? It looks parallel to me..

New theories propose that catastrophic impacts of asteroids and comets may have caused reversals in the Earth's magnetic field, the onset of ice ages, the splitting apart of continents 80 million years ago, and great volcanic eruptions.

Apologies OA is B not A. (that was a typo).

Please answer my question. I agree with the OA, but want to clarify a concept.

How do you choose between A and B ?

the sentence does say the onset ...... but it doesnt say the reversals or the great volcanic eruptions .

786 wrote:How do you choose between A and B ?

the sentence does say the onset ...... but it doesnt say the reversals or the great volcanic eruptions .

Its a parallelism in Noun form.

Splitting is a verb but according to grammer rules, adding THE to the progressive verb makes it noun or gerund to be precise.

The onset, reversal, eruptions and the splitting all are noun.

hope that helps!

yup

Can anyone tell me why C isn't correct?

"split apart continent" is definitely a verb here, not the gerund/noun that is required to maintain parallelism.

uwhusky wrote:"split apart continent" is definitely a verb here, not the gerund/noun that is required to maintain parallelism.

Isn't this correct:

New theories propose that catastrophic impacts of asteroids and comets may have caused split apart continents.

?

- He could see the split apart continents from the outer-space.

uwhusky wrote:"split apart continent" is definitely a verb here, not the gerund/noun that is required to maintain parallelism.

@uwhusky
C - I do not think that split apart in split apart continents is a verb.
This is because then, the sentence would completely break down. Notice the non underlined parts -
- caused reversals in the Earth's magnetic field, the onset of ice ages..., and great volcanic eruptions

The parallel parts here are -
Catastrophic impacts of asteroids and comets may have caused
1. reversals in the Earth's magnetic field (noun phrase)
2. the onset of ice ages (noun phrase)
3. great volcanic eruptions (noun phrase)

Now notice the underlined part in C-
split apart continents - if split is a verb, then we are introducing a verb and an object in between three parallel noun phrases. This cannot be correct.

Actually in option C, split apart is an adjective modifying continents. So split apart continents is a noun phrase.

clawhammer wrote:Can anyone tell me why C isn't correct?

@clawhammer -
As written above, in option C,
split apart continents is a noun phrase with split apart modifying continents. Hence, this is parallel with the other noun phrases. However, the meaning is distorted.

Notice the parallel structure -
Catastrophic impacts of asteroids and comets may have caused -
1) reversals in the Earth's magnetic field
2) the onset of ice ages
3) split apart continents
4) great volcanic eruptions

This would mean that asteroid impacts have caused split apart continents (adjective-noun). Now, clearly, impacts did not cause continents, rather impacts caused the splitting apart of continents.

That is why option C is wrong and B is right.

@niksworth

I guess we can agree that C is incorrect for different reasons. IMO, "split apart" to me is an incorrect usage of verb, thus C is wrong.

Edit: I just verified that this is indeed an OG question, which is question #119 (12th edition).

The explanation in the back of the book is also calling C an incorrect usage of verb.

I think if it is used as an adjective, it should be in participle like most verbs that are used as adjectives. Furthermore, GMAT makes it easier by using articles in front of the gerunds to signal that it is a gerund as oppose to a verb or verbal.

@uwhusky

Agreed. Since C is incorrect, the same phrase cannot be correct for one reason while incorrect for the other. It must be incorrect for both. Silly me

Nothing silly, good discussions!