In the washing machine task, which option is an example of a stimulus prompt?

• A. After closing the lid, Mary turns the dial to the correct setting by aligning two red arrows painted on the washer and dial before the session.
• B. The staff demonstrated pouring a small amount of milk into a cup.
• C. Mary completes the washing cycle with no cues.
• D. Mary uses verbal instruction to start the machine.

Answer: (A)

Stimulus prompts are cues added to the environment to make the correct response more likely by altering the antecedent stimulus. The option with two red arrows painted on the washer and dial provides a clear visual cue that guides Mary to align the dial with the correct setting before she acts. This cue is embedded in the task setup itself, changing what Mary sees and uses to choose the setting, which is exactly a stimulus prompt.

The other choices illustrate different prompting approaches or no prompting at all: demonstration of pouring milk is modeling, which teaches by showing the action; completing the cycle with no cues shows independence without prompts; verbal instruction to start the machine uses spoken guidance rather than a physical or environmental cue.