Which of the following illustrates an example of stimulus control?

The concept of stimulus control refers to the phenomenon where the behavior of an individual is influenced by the presence or absence of certain stimuli in the environment. In this case, the correct answer illustrates stimulus control because Joe's hitting behavior is specifically triggered by the teacher's request for him to wash his hands. This behavior occurs consistently in response to that particular stimulus, indicating that the action of asking about handwashing serves as a cue for Joe's response.

In the other scenarios, while behaviors are exhibited, they do not demonstrate the same clear relationship between a specific stimulus and a behavioral response. For example, the first option shows Joe hitting the teacher in response to a general inquiry about homework, which lacks the same direct stimulus-response connection that is present in the correct answer. The second option describes a general positive reaction to a teacher's request without specifying a consistent, controlled response to a specific stimulus. The fourth option shows a student's quiet behavior during a lesson, which does not emphasize a particular trigger for that behavior, thus lacking the clear stimulus control evident in the correct answer.