In contrast to vertically integrated companies that control every step of the supply chain for a limited product line, producing and marketing one product in a variety of ways enables horizontally integrated companies to increase market coverage and control a larger segment of the industry.

producing and marketing one product in a variety of ways enables horizontally integrated companies to increase market coverage and control
producing and marketing one product in a variety of ways enables horizontally integrated companies to increase market coverage, controlling
the producing and marketing of one product in a variety of ways enables horizontally integrated companies to increase market coverage, controlling
horizontally integrated companies, by producing and marketing one product in a variety of ways, are able to increase market coverage and control
horizontally integrated companies, by producing and marketing one product in a variety of ways, are able to increase market coverage and controlled

OA: D

In option C, I understand that the “companies” are illogically contrasted with “the producing and marketing of one product.” and that is incorrect.

But the explanation points out another error - “controlling” is not parallel with “to increase.” In case of 'ing' modifiers, my understanding is if one of the following conditions are present, its use is acceptable

1) the "ing" action is SIMULTANEOUS with the main action;
2. the "ing" action is a DIRECT CONSEQUENCE of the main action.

In this case, 'controlling a large segment of the industry' is a direct action of 'producing and marketing one product in a variety of ways'

So, why is the use of 'controlling' incorrect?

Source: mgmat

hey...it's a || issue...

just check in D...
"...........are able to increase market coverage and control....."

both verb are ||
we can avoid "to" before verb

E is not ||

Hope it helps!

i'm not convinced of your rule #2; can you provide a source or an example of where rule #2 is applied correctly? it seems more likely that you have the cause and effect backwards, i.e. that the thing modified by the -ing word would need to be a direct consequence of the -ing word and not the other way around..

_________________
Tim Sanders
Manhattan GMAT Instructor