According to Analysts.... Comparison

[nandy1984]

According to analysts, an alliance between three major personal computer companies and most of the nation's largest local telephone companies would enable customers to receive Internet data over regular telephone lines with speeds much higher than is currently possible.
A. with speeds much higher than is
B. with speeds that are much higher than are
C. at much higher speeds as are
D. at much higher speeds than that
E. at speeds much higher than are

Here i could eliminate
A: "is" wrong
B: wordy and awkward
C: higher should be followed by "than"

could not decide on D and E... Please explain...And if there can be any simple rule for these kind please do mention so that it helps in other problems....

[GmatKiss]

According to analysts, an alliance between three major personal computer companies and most of the nation's largest local telephone companies would enable customers to receive Internet data over regular telephone lines with speeds much higher than is currently possible.

A. with speeds much higher than is
B. with speeds that are much higher than are
C. at much higher speeds as are
D. at much higher speeds than that
E. at speeds much higher than are

IMO: D

[nandy1984]

According to analysts, an alliance between three major personal computer companies and most of the nation's largest local telephone companies would enable customers to receive Internet data over regular telephone lines with speeds much higher than is currently possible.

A. with speeds much higher than is
B. with speeds that are much higher than are
C. at much higher speeds as are
D. at much higher speeds than that
E. at speeds much higher than are

IMO: D

Answer is E

[Bill@VeritasPrep]

The problem with D is that "that" is singular. If it had said "at much higher speeds than those," it would be a better choice.

An easy way to catch that mistake is to ask what "that" refers to. We know we're talking about speeds; should we say "that speeds" or "those speeds?"