为自己加油

Choose the closest paraphrased version for the sentence or italicized part.

If they ［parents］ give in, they feel regret and resentment over having been a pushover.（）

A.
They make up their mind to be more strict.
B.
They never regret that they have given in.
C.
They feel upset that they haven’t been kind enough.
D.
They are sorry and angry that they haven’t been firm enough.