A puzzling SC

[papumba2011]

９． In the 1980's the rate of increase of the minority population of the United States was nearly twice as fast as the 1970's.
(A) twice as fast as
(B) twice as fast as it was in
(C) twice what it was in
(D) two times faster than that of
(E) two times greater than

Can someone help me out here with the answer along with proper explanation?

[neoreaves]

(A) twice as fast as two terms compared are not parallel ..."In the 1980s ..." indicates that there should be "in" in the parallel structure as well
(B) twice as fast as it was in correct
(C) twice what it was in "what" is considered awkward
(D) two times faster than that of "that" has no clear antecedent
(E) two times greater than again parallelism error

[kevincanspain]

A and E offer an invalid comparison: we want to compare two rates of increase, not a rate with a decade.

Rates are not fast, slow or prevalent, just as costs are not expensive and temperatures are not hot or cold

Thus B and D can be rejected

[pops]

wow... well spotted kevin..
rate cant be faster or slower !

[neonite]

Kevin, Thanks for the explanation.

One follow up question: If instead of "fast" we had "high", then would the statement be grammatically correct, since "rate of increase" can be "high" ?

(F) twice as high as the 1970s.

[aspirant2010]

Hi,

According to me answer should be C.......please post the OA.

[papumba2011]

OA C

As explianed by Kevin.