Which situation is considered reinforcement A. Earning an A despite not studying or listening in class B. Receiving a thank you from somebody after doing something nice C. Refusing to leave a tip for?

B. Receiving a thank you from somebody after doing something nice is considered reinforcement. In this context, the positive feedback serves to strengthen the behavior of being kind or helpful, making it more likely that the individual will engage in similar behaviors in the future. The other options do not involve a positive reinforcement that encourages a behavior.