Which of the following describes the state of affairs after conditioning?

a. CS-CR

b. US-CR

c. CS-UR

d. US-UR

I believe the answer is: CS-CR

Classical conditioning occurs when conditioned stimulus (CS) is paired with conditioned response. (CR). Conditioned stimulus refers to the type of trigger that are purposefully designed by the researchers to alter the subject behavior. conditioned response is the altered behavior that the subject made in response to the conditioned stimulus.

For example, in Pavlov dog's experiment, ringing the bell before giving the food is conditioned stimulus and the dogs' watering mouth every time they hear the sound of the bell is the conditioned response.