you may have， you should gather your courage to face the challenge.
A. However a serious problem
B. What a serious problem
C. However serious a problem
D. What serious a problem
网友回答
A. However a serious problem
B. What a serious problem
(答案→)C. However serious a problem
D. What serious a problem
解析：考查让步状语从句。本句是一个让步状语从句，单个的what是不能引导让步状语从句的。However可以引导让步状语从句，所修饰的形容词或副词要紧跟在however的后面。句意：无论你有多么严重的问题，你都应该鼓起勇气去面对挑战。故C正确。