A pigeon in operant chamber #1 regularly receives a pellet of food after every ten pecks at a red disk, no matter how long it takes. A rat in operant chamber #2 regularly receives a pellet of food for the first bar press it makes after ten minutes have passed, no matter how many bar presses it makes. The pigeon is on a _____ schedule of reinforcement, and the rat is on a _____ schedule of reinforcement.
A)fixed-ratio; fixed-interval
B)fixed-interval; fixed-ratio
C)fixed-ratio; variable-interval
D)fixed-ratio; variable-ratio