Question

the skinner box allowed researchers to
control the exercise of subjects for extended periods.
offer food to subjects when the right lever was pushed.
keep the subjects from any food for extended periods of time.
control the external stimulation of subjects for brief periods.

Explanation:

The Skinner Box (operant conditioning chamber) is used to study operant conditioning. In it, when an animal (subject) performs a desired behavior (like pushing a lever), a reinforcer (often food) is provided. Option 1 is incorrect as it's not about exercise control. Option 3 is incorrect as it's not about depriving food but about reinforcing behavior with food. Option 4 is incorrect as it's for controlling stimulation (to study behavior) over periods (not just brief) to observe how behavior is shaped by consequences. Option 2 correctly describes that when the right lever (desired behavior) is pushed, food (reinforcer) is offered.

Answer:

B. offer food to subjects when the right lever was pushed.