Now you have to do is to admit your mistakes and immediately correct them.
A. that
B. whether
C. what
D. how
网友回答
A. that
B. whether
(答案→)C. what
D. how
解析：考查名词性从句。句意：现在你不得不做的就是承认你的错误，并立即更正。What引导主语从句，并在从句中作do的宾语。What可引导主语从句、宾语从句、表语从句、同位语从句，并在从句中做主语或宾语，但不引导定语从句。故选C。