Question

"five-year-old trevor is emotionally disturbed and refuses to communicate with anyone. to get him to speak, his teacher initially gives him candy for any utterance, then only for a clearly spoken word, and finally only for a complete sentence. the teacher is using the method of"

Answer 1

Positive reinforcement
Positive reinforcement is adding a reinforcing stimulus (candy) that is desirable or wanted by the individual.  The positive reinforcement is given after a desired behavior.  The positive reinforcement makes it more likely for the behavior to occur again.