An auxiliary verb is a verb that is used along with another main verb to form tenses, negatives, and questions. Examples are: 'be', 'have' and 'do'. It usually comes before the main verb.
The main verb in the given sentence is "done", which is the past participle form of the verb 'do'. Hence, we know that the sentence is either in the present perfect tense or the past perfect tense. We know that the appropriate form of the auxiliary verb, 'have' is used to form perfect tenses. And the auxiliary form of 'do' is not used. Hence, Options A and B are incorrect.
If the subject is in the third person singular form, the auxiliary verb, 'has' is used. Otherwise, the auxiliary verb, 'have' is used. Here the subject is 'you', which is in the second person. Hence, 'has' cannot be used and 'have' is the suitable auxiliary verb. Hence, option C is correct and Option D is incorrect.