The conditioned stimulus is defined as:

A) the stimulus that automatically produces the unconditioned response.
B) the previously neutral stimulus that automatically produces the unconditioned response.
C) the previously neutral stimulus that has acquired the capacity to produce the conditioned response.
D) the stimulus that remains neutral throughout classical conditioning.

Answer: C
Rationale: A conditioned stimulus (CS) is a once neutral stimulus that elicits a conditioned response because it has a history of being paired with an unconditioned stimulus.