Answer:
Juan is characterized by intrinsic motivation.
Step-by-step explanation:
The intrinsic term refers as something that comes from within. Intrinsic motivation is what gives one the impulse to pursue what gives him/her a satisfactory reward.
Juan is taking the chemistry course because he has a love for the subject, unlike David who is taking it because of a suggestion. In the end, it is possible that Juan will take more advantage of the course because he is driven his love for it and the reward of learning about it.