As is the case for other volcanoes in the Cascade Range, Mount St.

As is the case for other volcanoes in the Cascade Range, Mount St. Helens consists of a large eruptive cone containing lava rock interlayered with ash, pumice, and other deposits, is part of the Pacific Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean.

To compare nouns , we need LIKE
SPLIT 1 # as is the case / similar / Like eliminate A and B
C - incomplete sentence when read along with the non underlined part
D - correct . Correct noun comparator LIKE , ,which modifies Mount St. Helens
E - error in idiom - consists of is correct , not consists in a large eruptive cone and contain … changes meaning of the sentence . Illogical


Answer is D

(A) As is the case for other volcanoes in the Cascade Range, Mount St. Helens consists of a large eruptive cone containing

(B) Similar to other volcanoes in the Cascade Range, Mount St. Helens consists in a large eruptive cone that contains

(C) Like other volcanoes in the Cascade Range, Mount St. Helens consists of a large eruptive cone that

(D) Like other volcanoes in the Cascade Range, Mount St. Helens, which consists of a large eruptive cone containing

(E) Like other volcanoes in the Cascade Range, Mount St. Helens, which consists in a large eruptive cone and contain

Official Explanation :

Choice A is incorrect because it creates a nonsense fragment when it is read in context of the sentence as a whole. Be careful with this answer, though: even though it is somewhat wordy, it appears to be grammatically acceptable when read only in the context of the beginning of the sentence. The problem can be seen more easily if the sentence is stripped down to its basic components: Mount St. Helens consists of a large eruptive cone... is part of the Pacific Ring of Fire.

Choice B is incorrect because it creates the same grammatical problem as choice A. The use of similar to form the comparison is acceptable, but it is a distraction that does not address the underlying problem consists in should be consists of.

Choice C is incorrect because it creates the same grammatical problem as choice A and B. Even though like normally signifies correctly formed transition in the GMAT, in this case the formation of the comparison is secondary to the issue and the sentence does not make grammatical sense.

Choice D is correct because the insertion of which creates a non-essential clause that, when removed, leaves a grammatically coherent sentence: Like other volcanoes in the Cascade Range, Mount St. Helens,...is part of the Pacific Ring of Fire.

Choice E is incorrect because of the formation of the non-essential clause: consists in should be consists of, and contain should be contains because the existing verb is not parallel to consists and disagrees with its subject Mount St. Helens.