Answer:
C. Jason brought three sandwiches for himself.
Explanation:
Reflexive Pronouns are pronouns used when the subject and the object of a sentence are the same: they turn the action back on the subject. We can easily identify them because they start and end with the suffix -self (singular) or -selves (plural): myself, yourself, herself, himself, itself, themselves, yourselves and ourselves.
Sentence C is the one that uses the reflexive pronoun correctly because the subject Jason and the object himself are the same, and the fuction of this latter is to turn the action back on the subject.