match the followings:
| A. Unconditioned Stimulus (UCS) | I. A stimulus that naturally and automatically triggers a response. |
| B. Conditioned Stimulus (CS) | II. The learned response to a previously neutral stimulus. |
| C. Conditioned Response (CR) | III. A previously neutral stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response. |
| D. Unconditioned Response (UCR) | IV. An unlearned response that occurs naturally in reaction to the unconditioned stimulus. |
1
A-I, B-II, C-III, D-IV
2
A-IV, B-II, C-I, D-III
3
A-I, B-III, C-II, D-IV
4
A-IV, B-I, C-II, D-III