The correct answer would be, Being negatively reinforced for complaining about his stomach.
Each time the teacher sends him to the school nurse without completing his work and without being penalized, San is being negatively reinforced for complaining about his stomach.
Explanation:
Negative Reinforcement and Positive Reinforcement are the concepts of Operant Conditioning that were given by B.F.Skinner. Operant Conditioning is basically a learning process in which the behavior of a person or animal is strengthened either by reinforcement or punishment.
So when Sam was sent to the school nurse in the middle of exam or any difficult assignment, and was not given any penalty or punishment, then his this negative behavior is reinforced and he continues to do this.
Learn more about Negative Reinforcement at:
https://brainly.com/question/13767737
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