Answer:
C). Negative Reinforcement.
Explanation:
Reinforcement is demonstrated as the process through which the probability of a particular outcome or behavioral response is increased or strengthened. However, the reinforcement techniques or methods could be positive(rewards or admiration) or negative(when the unfavorable stimulus that may prevent the desired outcome is removed).
In the given example, the 'negative reinforcement' could be applied to the mother's way of strengthening the outcome of desired behavior from her child as she removes the unfavorable stimulus by 'giving him the toffee' to get the desired outcome from the child('stop whining'). This leads to negative consequences as the child uses it as a tool to get his things done. Therefore, option C is the correct answer.