I'm pretty sure it's C, it makes the most sense.
Answer:
RESPONDENT ; OPERANT
Explanation:
A light goes on in a room just before an excruciatingly loud buzzer sounds. A subject who startles when the light goes on shows RESPONDENT behavior, but one who leaves the room to avoid the noise exhibits OPERANT behavior.
RESPONDENT BEHAVIOR are behaviors that you may not have full control of, they are like reflexes. While OPERANT BEHAVIOUR are all behaviors that can be controlled, and are voluntary.
Answer:
A long narrow stretch of Hills is called ridge.
