The correct answer is A) the overjustification effect.
Zoe, a teenager, likes to help her mother in the kitchen, and her parents reward her with pocket money for doing so. Zoe thinks she helps in the kitchen because of the rewards rather than because she wants to. In the context of socializing altruism, Zoe's act is due to the overjustification effect in this scenario.
Sociologists have studied this kind of behavior and have given it a name: the overjustification effect. People in this scenario expect an external incentive such as money or public recognition when doing things. Instead of doing things because it's their duty or the satisfaction to help another person, these people are looking for a reward. So they are conditioning their help.