Sentences that use "Not only X, but also Y" must provide parallel X and Y. We can use this to eliminate B: "Not only did the clearing create...but also caused". Should be "but it also caused"

C is a sentence fragment because the main clause doesn't have a working verb. The sentence core in C says "The clearing...but also caused erosion"

E is incorrect because it fails to properly express the relationship between "to create farmland" and "to give consumers houses". The intended meaning is that the clearing of forests did both of these things, so the things in question should be listed in parallel. E states "created farmland, giving consumers houses". This construct puts the 2nd part in a modifier, as if 'giving consumers' were a result of 'created farmland'. The right answer must list the two actions in parallel because they are logically equivalent: they are both the effects of the clearing of forests.

This leaves us with A or D.

A actually makes the same error as E although it's more difficult to see. The two actions that are the result of the clearing of forests should be expressed in parallel: "create farmland...and give consumers houses". This would imply "did create...did give" A is incorrect because it switches from "create" to "gave"

D is correct. This is Question ID 2118

-Patrick

gmat_perfect wrote:Not only did the systematic clearing of forests in the United States create farmland (especially in the Northeast) and gave consumers relatively inexpensive houses and furniture, but it also caused erosion and very quickly deforested whole regions.

A. Not only did the systematic clearing of forests in the United States create farmland (especially in the Northeast) and gave consumers relatively inexpensive houses and furniture, but it also
B. Not only did the systematic clearing of forests in the United States create farmland (especially in the Northeast), which gave consumers relatively inexpensive houses and furniture, but also
C. The systematic clearing of forests in the United States, creating farmland (especially in the Northeast) and giving consumers relatively inexpensive houses and furniture, but also
D. The systematic clearing of forests in the United States created farmland (especially in the Northeast) and gave consumers relatively inexpensive houses and furniture, but it also
E. The systematic clearing of forests in the United States not only created farmland (especially in the Northeast), giving consumers relatively inexpensive houses and furniture, but it

correct idiom: not only x but also y => E out
A - create & gave not llel=> out; B - which modifies farmland...meaning farmland gave consumer; C - creating & giving modiies a phrase rather than clause

IMO D