An action in a sentence can be represented in two ways, namely active and passive voice.

The passive voice always uses the past participle form of the main verb irrespective of any tense. Only the auxiliary verbs depend upon the sentence given in the active voice.

The option C is correct as the given sentence is in the active voice and to transform it into passive voice the subject of the given sentence 
(someone) comes in the place of the object (you) and vice-versa.

Also, as the given sentence is in the simple present tense and the conjunction 'until' is used, the helping verb 'have' (because of until) is followed by 'been'. 

Options A, B, and D are wrong as the helping verb used in the transformed sentence (will be) is not appropriate, the subject is not in its place, and the subject is not its place with the appropriate helping verb respectively.

The correct answer is C)Don't speak until you have been spoken to.