The correct option is C is making
The tense of a sentence denotes a time, whether it is the time now (present), time then (past) or the time to come (future). The verb of a sentence has most to do with the tense. In the given sentence, we need to fill in a word that determines the correct tense. The speaker told John to "speak up", in other words, speak loudly because John's dog was making too much noise. This action is in the present tense, as John is speaking and the dog is making too much noise at the moment. 'Speak up' is in the simple present tense, as John is not speaking at the moment, but, the dog is making noise, hence we need a verb in the present continuous tense, to refer to "too much noise". 'Makes' is in the simple present tense, to refer to a general truth, a habit or custom, example, 'she makes coffee for everyone every morning'. Here, the situation isn't the same, the action is a continuous one, hence option A is incorrect. 'Made' is in the past tense, whereas the action is in the present, hence option B is incorrect. 'Is making' is in the present continuous tense, referring to the dog making noise at that moment, hence option C is correct. 'Has made' is in the present perfect tense, whereas the action the dog is making is a continuous one, hence option D is incorrect.