(单选题)35:     Our child's behavior is greatly influenced by the way we react to what he has done. Our reactions help to determine whether our child will repeat his behavior or whether he will do something different. This statement is a very important part of a principle of behavioral psychology.     The principle states that a behavior is influenced or affected by how the environment ---- people, places and things ---- immediately responds to the behavior. Perhaps without realizing it, you have used this principle many times.     On the occasion when you told your child what a good boy he was after he cleaned up his room, you used the principle. When you sent your child to his room for fighting with his brother, you used the principle. When I gave Kim a cookie after she started to cry, I used the principle. In each of these examples, a particular behavior occurred first ---- cleaning up a room, fighting, and crying.In addition, there was a reaction to each behavior ---- the child was praised, sent to his room, or given a cookie. By these actions, we have influenced the previous behaviors and have helped to determine whether those behaviors will occur again in the future.                                                                                                                                              (2) On what kind of principle is the lecture based?

A: A principle in chemistry.

B: A principle in behavioral psychology.

C: A principle in physics.

D: A principle in geology.