The correct option is C himself
Here, 'himself' as a Reflexive Pronoun is correct because it is used when the man or boy who performs an action is also affected by it.
'Him' is incorrect because it is used as the object of a verb, after the verb be or after a preposition to refer to a male person or animal that has already been mentioned or is easily identified.
'His' is incorrect because it implies of or belonging to a man or boy who has already been mentioned or is easily identified.
'He' is incorrect because it implies a person, male or female, whose sex is not stated or known, especially when referring to somebody mentioned earlier or to a group in general.