Answer:
Intrinsic
Step-by-step explanation:
Motivation is the reason a person has in order to do something. There are two types of motivation
Intrinsic
This type of motivation is the motivation that comes from within one's self. It is done for getting satisfaction for one's self.
Extrinsic
This type of motivation is the motivation that occurs by external factors.
Here, Juan's own love of science motivates him to take advanced placement chemistry classes. Whereas David's motivation is that in order to apply to a pre-med program at a competitive university he needs to take advanced placement chemistry which is an external factor.
Hence, Juan is motivated by intrinsic motivation.