Bunuel
Earthworms play an essential role in the soil ecosystem, feeding on organic residue and recycling nutrients back into soil;
increasing rainwater absorption through soil aeration, soil loosening, and soil tunneling; and promoting flowering, root development, and overall plant health by fertilizing the soil with a unique waste product called castings.
(A) increasing rainwater absorption through soil aeration, soil loosening, and soil tunneling; and promoting
(B) they increase rainwater absorption through soil aeration, soil loosening, and soil tunneling; and promote
(C) they increase rainwater absorption through soil aeration, soil loosening, and soil tunneling and promoting
(D) increasing rainwater absorption through soil aeration, soil loosening, and soil tunneling and promoting
(E) increasing rainwater absorption through soil aeration, soil loosening, and soil tunneling, and promoting
VERITAS PREP OFFICIAL SOLUTION:
In analyzing the different decision points in the answers, it is clear that this question is primarily testing sentence construction – you need to make sure the different elements are logically linked with a parallel structure. The original sentence presents a list of participial phrases that convey how the earthworms play an essential role in the soil ecosystem. The first part of that list – “feeding on organic residue and recycling nutrients back into the soil” – is not underlined, so what follows must be parallel to it.
Confusingly, the first part of the list also ends with a semi-colon, which is usually used to link together two independent clauses but can also be used to link complex elements in a series. The two remaining elements of the list are both parallel to the first and linked properly with a second semi-colon, which is appropriate when you are linking together multiple elements that themselves contain commas. As a result, the original (A) is correct.
For (B), two semi-colons are again used, and this requires that three parallel elements be linked together. Since the three elements are clearly not parallel, it is incorrect.
For (C), (D), and (E) there is only one semicolon in the sentence: this means that what follows the semi-colon must be an independent clause linked to the first. For (C), “they increase…and promoting” is illogically linking two parts of the series into one independent clause – they are clearly two separate things that need to be linked back separately to the first. Both (D) and (E) lack a main verb to create a separate independent clause to be linked with the first.
Correct answer is (A).