A Discriminative Stimulus Is Best Described As

A discriminative stimulus is best described as:

A) a stimulus that provides the organism with a cue for making a certain response in order to obtain reinforcement.
B) as any object,event,or experience that causes a response,or a reaction of an organism.
C) a stimulus that cues the person about which schedule of reinforcement is being used in operant conditioning.
D) the stimulus that Watson used to make Little Albert scared of all fuzzy things.