For the farmer who takes care to keep them cool,
providing them with high-energy feed, and milking them regularly, Holstein cows are producing an average of 2,275 gallons of milk each per year.
(A) providing them with high-energy feed, and milking them regularly, Holstein cows are producing
(B) providing them with high-energy feed, and milked regularly, the Holstein cow produces
(C) provided with high-energy feed, and milking them regularly, Holstein cows are producing
(D) provided with high-energy feed, and milked regularly, the Holstein cow produces
(E) provided with high-energy feed, and milked regularly, Holstein cows will produce
Source : GMATPrep Default Exam PackAt first, none of the answers looks right - this is certainly a high level question. B) and D) cannot be correct, as mentioned above, because the sentence has a plural number of cows ('them') at the beginning of the sentence, and a singular number of cows at the end. A) doesn't look at all promising, because, if you interpret 'takes care', 'providing' and 'milking' to be a list of actions performed by the farmer, you expect parallelism; that is, you expect it to read: "takes care to keep them cool, provides them with high energy feed, and milks them regularly..." Unfortunately none of the answers is parallel in this sense, *so we can't interpret the underlined passage as part of a sequence of actions performed by the farmer*. The underlined passage isn't attached to the beginning of the sentence at all, in fact; it's attached to the end of the sentence. If we simply reorder the words, using what should be the correct answer (that's E), I assume), the meaning should become clear:
Try to do the same rearrangement with answer A) and you'll see there's a problem.