Tektites

Tektites, which may have been propelled to Earth from lunar volcanoes, are much like the volcanic glass obsidian, but their chemical composition is different than any terrestrial lava; they contain far less water than obsidian does and none of its characteristic microcrystals.

(A) is different than any terrestrial lava; they contain

(B) is different than any terrestrial lava's, containing

(C) is different from that of any terrestrial lava; they contain

(D) differs from any terrestrial lava in containing

(E) differs from that of any terrestrial lava's, containing


so IMO C

Looking for a better explanation

A) "...different than..." - incorrect
B) "...different than..." - incorrect
C) CORRECT
D) "... chemical composition ... terrestrial lava" - wrong parallelism
E) I think that the usage of "lava's" to refer to its chemical composition is correct but the "containing" after the comma seems to refer to the chemical composition instead of Tektites.

Any comment regarding the usage of "lava's" in E) ?

GmatKiss wrote:Tektites, which may have been propelled to Earth from lunar volcanoes, are much like the volcanic glass obsidian, but their chemical composition is different than any terrestrial lava; they contain far less water than obsidian does and none of its characteristic microcrystals.

(A) is different than any terrestrial lava; they contain

(B) is different than any terrestrial lava's, containing

(C) is different from that of any terrestrial lava; they contain

(D) differs from any terrestrial lava in containing

(E) differs from that of any terrestrial lava's, containing

A and D incorrectly compare chemical composition to lava. When a sentence makes a comparison, it must compare APPLES to APPLES. Eliminate A and D.

COMMA + VERBing generally refers to the subject of the preceding clause. Thus, in B and E, containing refers to composition, implying that the COMPOSITION is containing far less water than obsidian. The composition itself does not CONTAIN far less water; the TEKTITES do. It is illogical to compare composition to obsidian. Eliminate B and E.

The correct answer is C.

Other errors:

In A and B, different THAN is incorrect. To convey that X and Y are different, we say that X is different FROM Y.

In E, that OF and lava'S are redundant. Eliminate E.

Different from Correct idiomatic format

As the sentence is about comparison " that of any terrestrial" Correctly compares the chemical composition.

[quote="GMATGuruNY"][quote="GmatKiss"]Tektites, which may have been propelled to Earth from lunar volcanoes, are much like the volcanic glass obsidian, but their chemical composition [u]is different than any terrestrial lava; they contain[/u] far less water than obsidian does and none of its characteristic microcrystals.

(A) is different than any terrestrial lava; they contain

(B) is different than any terrestrial lava's, containing

(C) is different from that of any terrestrial lava; they contain

(D) differs from any terrestrial lava in containing

(E) differs from that of any terrestrial lava's, containing[/quote]

A and D incorrectly compare [i]chemical composition[/i] to [i]lava[/i]. When a sentence makes a comparison, it must compare APPLES to APPLES. Eliminate A and D.

COMMA + VERBing generally refers to the subject of the preceding clause. Thus, in B and E, [i]containing[/i] refers to [i]composition[/i], implying that the COMPOSITION is [i]containing far less water than obsidian[/i]. The [i]composition[/i] itself does not CONTAIN far less water; the TEKTITES do. It is illogical to compare [i]composition[/i] to [i]obsidian[/i]. Eliminate B and E.

The correct answer is [spoiler]C[/spoiler].

Other errors:

In A and B, [i]different THAN[/i] is incorrect. To convey that X and Y are different, we say that [b]X is different FROM Y[/b].

In E, [i]that OF[/i] and [i]lava'S[/i] are redundant. Eliminate E.[/quote]

Is the pronoun, "they", in ans choice C vague? I eliminated C for the reason it did not have a clear antecedent

quriousaddict wrote:Is the pronoun, "they", in ans choice C vague? I eliminated C for the reason it did not have a clear antecedent

Here's the core structure of the OA:

TEKTITES are much like the volcanic glass obsidian, but THEIR chemical composition is different from that of any terrestrial lava; THEY contain far less water than obsidian does and none of its characteristic microcrystals.

It seems clear that the antecedent of their and they is tektites.