Five-Year-Old Trevor Is Emotionally Withdrawn and Refuses to Communicate with Anyone.To

Multiple Choice

Five-year-old Trevor is emotionally withdrawn and refuses to communicate with anyone.To get him to speak,his teacher initially gives him candy for any utterance,then only for a clearly spoken word,and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

A) secondary reinforcement.
B) delayed reinforcement.
C) spontaneous recovery.
D) shaping.