Final answer:
The correct option is (a) Incentives.
External stimuli or rewards motivating behavior are called incentives. These can be tangible, like money, or intangible, such as praise, and serve as motivational factors in both expected and unexpected forms.
Step-by-step explanation:
The external stimuli or rewards which we desire and that can motivate behavior are called incentives. These incentives can be tangible, such as money, toys, or praise, or they can be intangible, like a sense of achievement or recognition. An incentive motivates an individual to pursue a goal or to behave in a certain way. Consequently, answering the multiple-choice question presented, the correct option is (a) Incentives. For example, if a student is promised a reward for good grades, the prospect of receiving this reward serves as an external motivation to excel academically.
Moreover, when such incentives are unexpected, they can support intrinsic motivation rather than undermining it. This concept aligns with research that has found tangible rewards can sometimes diminish intrinsic motivation, whereas intangible rewards like praise may not have the same effect. Concrete rewards, like praise or a toy, can serve as positive reinforcement, encouraging a desired behavior to be repeated in the future.