When Would You Expect the Greatest Degree of Stimulus Generalization

Multiple Choice

When would you expect the greatest degree of stimulus generalization in classical conditioning

A)  when auditory stimulation is used rather than visual stimulation 
B)  when tactile stimulation is used rather than auditory stimulation 
C)  when stimuli are very similar to the original conditioned stimulus 
D)  when stimuli are very different from the original conditioned stimulus