Final answer:
A changing criterion experimental design would be most beneficial to use for behavior that needs to be systematically shaped or gradually modified.
Step-by-step explanation:
A changing criterion experimental design would be most beneficial to use for behavior that needs to be systematically shaped or gradually modified (option C). Changing criterion design is a type of experimental design that involves gradually changing the criteria for reinforcement or punishment in order to shape or modify a behavior. This type of design allows for precise control over the shaping process and is often used when the behavior to be modified is complex and requires successive approximations (steps) to reach the target behavior.