How should a teacher react, if parents demand changes in his teaching?

A positive teacher accepts feedback from all people as long as such feedback is constructive and does not conflict with teaching standards and ethics. Accordingly, if such demand is logical, constructive and correct, the teacher shall absolutely welcome the same; however, if it is an arbitrary demand or would lead to incorrect practices, I think the teacher can decline the same indirectly, in a way to keep good terms with the parents. It will be nice if the teacher set with the parents to explain his viewpoint in gentle manner, so that to gain the confidence of parents.