When does extinction of a conditioned response in classical conditioning occur

A)  when the CS is occasionally presented without the UCS 
B)  when the CS is repeatedly presented without the UCS 
C)  when the UCS is repeatedly presented without the UCR 
D)  when the UCS is occasionally presented without the UCR

Extinction

In psychology, the gradual weakening and eventual disappearance of a conditioned response when the conditioned stimulus is presented without the unconditioned stimulus.

Classical Conditioning

A method where learning occurs by continuously associating two stimuli, making a response that was elicited by the second stimulus to be elicited by the first stimulus over time.

Conditioned Response

A response that is acquired after a previously neutral stimulus becomes linked with a stimulus that naturally induces a reaction.