twice as likely as 这种表达正确吗？

fusiyu

42.According to a survey of graduating medical students conducted by the Association of American Medical Colleges, minority graduates are  
nearly four times more likely than are other graduates in planning to practice in socioeconomically deprived areas.  
(A) minority graduates are nearly four times more likely than are other graduates in planning to practice  
(B) minority graduates are nearly four times more likely than other graduates who plan on practicing  
(C) minority graduates are nearly four times as likely as other graduates to plan on practicing  
(D) it is nearly four times more likely that minority graduates rather than other graduates will plan to practice  
(E) it is nearly four times as likely for minority graduates than other graduates to plan to practice  
the key: C  

刘振民语法书，E9-45说："twice 一般用于数量上的翻倍，仅可以说twice as much as, or twice as many as;绝不可以对形容词或副词翻倍：如twice as fast as..."

请问上题D为什么错？

FlowerJay

rather than只能单用， 不能用 more... rather than。。 我记得