What type of discriminative stimulus (SD) typically prompts a vocal echoic response?

The type of discriminative stimulus that typically prompts a vocal echoic response is auditory. An echoic response occurs when an individual hears a verbal stimulus and then repeats it back. This process is characterized by the auditory nature of the prompt, as it relies on the individual’s ability to hear and subsequently vocally replicate what was heard.

While visual and tactile stimuli can elicit different types of responses, they do not specifically lead to echoic behavior. Echoics are inherently linked to the auditory modality, where the individual listens to speech and performs an echoic response by vocally mimicking it. Therefore, the auditory discriminative stimulus is essential for initiating this particular verbal operant, making it the correct choice.