帮忙挑战一下GMAT语法吧

Hema

Q1:
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
这个题我选的是B,我觉得B比E清楚很多，为什么答案选E呢？
2.Heirloom tomatoes, grown from seeds saved from the previous year, only look less appetizing than their round and red supermarket cousins, often green and striped, or have plenty of bumps and bruises, but are more flavorful.

A. cousins, often green and striped, or have plenty of bumps and bruises, but are
B. cousins, often green and striped, or with plenty of bumps and bruises, although
C. cousins, often green and striped, or they have plenty of bumps and bruises, although they are
D. cousins; they are often green and striped, or with plenty of bumps and bruises, although
E. cousins; they are often green and striped, or have plenty of bumps and bruises, but they are
or have不是谓语的并列吗？为什么要加逗号？从这个明确清楚的角度来讲，e是比其他都表达清楚。
3.When drive-ins were at the height of their popularity in the late 1950’s, some 4,000 existed in the United States, but today there are less than one-quarter that many.

A. there are less than one-quarter that many
B. there are fewer than one-quarter as many
C. there are fewer than one-quarter of that amount
D. the number is less than one-quarter the amount
E. it is less than one-quarter of that amount
D为什么不对？C是什么结构？