答案及解析：[单选题]According to Dr. David Wash, what should parents do to train children’s self-control ability? AFulfi

问题：

[单选题]According to Dr. David Wash, what should parents do to train children’s self-control ability?
AFulfill the child’s need whenever she asks for it
BFulfill the child’s need if she begs for it repeatedly
CPromise a reward if the child behaves herself, but do not actually deliver the reward
DPromise a reward if the child behaves herself, and deliver the reward if she makes it