The correct option is C passed out
A phrasal verb is a verb combined with an adverb or preposition to
provide a meaning different from the literal meaning of that individual
verb. The underlined phrasal verb 'passed away' means 'to die', this phrase isn't relevant here as it's mentioned later that the boy wakes up, hence this phrase needs to be changed and option A is incorrect. 'Passed out' means 'to become unconscious', it is relevant here as the gradual result of not eating and being tensed. Hence option B is correct. 'Pass out' is in the present tense meaning the same as 'passed out', whereas the sentence is in the past tense, as it refers to an incident that has already taken place, hence option C is incorrect. 'Pass up' means 'to reject something', like a job offer. It does not relate to the sentence, hence option D is incorrect.