you may have, you should gather your courage to face the challenge.
A. Whatever serious a problem
B. However serious a problem
C. However a serious problem
D. No matter how a serious problem
网友回答
A. Whatever serious a problem
(答案→)B. However serious a problem
C. However a serious problem
D. No matter how a serious problem
解析：考查让步状语从句：句意：无论你可能遇到多么严重的问题，你都要鼓足勇气面对挑战。Whatever后面接名词，排除A。however/no matter how后面可以接adj+冠词+名词，CD都是错的，选B。