Let us appreciate that the verb in the text is the plural ‘
cost ‘ and so we do need a plural subject here. All choices starting with singular subjects such as ‘
maintaining’ and ‘
to maintain’ are out (C, D and E)
Between A and B, B maintains the comparison llism by comparing what small classrooms do with what regular sized classrooms do.So B.
Perhaps forum members may be interested in an OG 10 question that is somewhat similar to this and I wouldn’t like to preempt its answer.
Dirt roads may evoke the bucolic simplicity of another century, but financially strained townships point out that dirt roads cost twice as much as maintaining paved roads.
(A) dirt roads cost twice as much as maintaining paved roads
(B) dirt roads cost twice as much to maintain as paved roads do
(C) maintaining dirt roads costs twice as much as paved roads do
(D) maintaining dirt roads costs twice as much as it does for paved roads
(E) to maintain dirt roads costs twice as much as for paved roads