( )bright you may be, you can not possibly know everthing. (although, instead, despite, however)

However ！
这里However用作连词(conj.)
后面可接形容词！

可以引导条件状语从句

还有，最重要的：
However ... may be 是一个词组
如
"However sly a fox may be, it is no match for a good hunter."
狐狸再狡猾也敌不过好猎手。

However.
1,它可以引导条件状语从句
2,instead,although,despite只能引导句子.本题连主语都没有.
所以都不对.

As