Sentence Correction

In a press conference given last week, the Mills Company spokesperson explained that although other machines are cheaper,the competitor's machines costs twice as much as maintaining the new Mill's machine

A. the competitor's machines costs twice as much as maintaining the new Mill's machine
B. the competitor's machines costs twice as much to maintain as the new Mill's machine
C. maintaining the competitor's machines costs twice as much as the new Mill's machine does
D. maintaining the competitor's machines costs twice as much as it does for maintaining the new Mill's machine
E. to maintain the competitor's machines costs twice as much as for the new Mill's machine

IMO C

bharath2787 wrote:In a press conference given last week, the Mills Company spokesperson explained that although other machines are cheaper,the competitor's machines costs twice as much as maintaining the new Mill's machine

A. the competitor's machines costs twice as much as maintaining the new Mill's machine
B. the competitor's machines costs twice as much to maintain as the new Mill's machine
C. maintaining the competitor's machines costs twice as much as the new Mill's machine does
D. maintaining the competitor's machines costs twice as much as it does for maintaining the new Mill's machine
E. to maintain the competitor's machines costs twice as much as for the new Mill's machine

You need to comprehend what the sentence is trying to imply.
I believe we are trying to compare "Cost of maintaining competitor machine" and "cost of maintaining Mill's machine"

Only C & D come close to the above mentioned comparison.

C rightly does by including 'does' making the sentence concise.

What is the OA?

OA C .
but doesn't C suggest that maintaining X costs twice than the Y machines cost ? ..

i think we need to compare the maintenance costs of both but not maintenance cost of one and the cost of the machine of another one!..

so i picked D, although it is long. what do you think ?