请教天山4-22 答案是否错了?

Q22:
Unlike mainstream American businesses, more than half of which fail, the failure rate for
businesses in the Amish community hovers around 5 percent.
A. Unlike mainstream American businesses, more than half of which fail
B. Unlike mainstream American businesses, in which the failure rate is more than
half
C. Unlike mainstream American businesses, where more than half of them fail
D. While the rate of mainstream American businesses failing is more than half
E. While more than half of mainstream American businesses fail
答案是E

但我觉得是B因为未化线部分主语是RATE

请牛牛解答

为什么这题没人问?

答案应该是E

Unlike mainstream American businesses, more than half of which fail, the failure rate for
businesses in the Amish community hovers around 5 percent.
答案A. 用mainstream American businesses与the failure rate比较，比较对象不一致
答案B. in which是非限制型定语从句修饰mainstream American businesses,可看作是插入成分，所以B与A的错误一样，都是用mainstream American business与the failure rate比较
答案C. 不仅A与B的错误未纠正，而且在where more than half of them fail也错，where表示地点，而此处不能用where引导
答案D. the rate of mainstream American businesses failing的表达不好（n+prep+n+分词），而且more than half也不能用来表示比例吧
答案E. 用While引导让步状语从句，语法没有问题