What conditioning involves associating a neutral stimulus with a natural response?

Classical conditioning is the correct answer because it involves learning through the association of a neutral stimulus with an unconditioned stimulus that naturally elicits a response. In this process, the neutral stimulus, after being paired repeatedly with the unconditioned stimulus, eventually evokes a similar response even in the absence of the unconditioned stimulus. This concept was famously illustrated in Ivan Pavlov's experiments with dogs, where he paired the sound of a bell (the neutral stimulus) with the presentation of food (the unconditioned stimulus), leading the dogs to salivate (the conditioned response) merely upon hearing the bell.

In contrast, operant conditioning focuses on learning through the consequences of behavior, where behaviors are modified by rewards or punishments. Direct instruction involves a more structured teaching method without the association element found in classical conditioning. Sensory memory pertains to the brief retention of sensory information and does not relate to the conditioning process or the association of stimuli. Thus, classical conditioning is the process where a neutral stimulus becomes significant through its association with a naturally occurring response.