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
(I) comes in the place of the object (you) and vice-versa.
Also, as the given sentence is in the simple present tense, 'are' is used before the past participle form of the main verb (expect).
Options A, B, and D are wrong as the subject is not in its place in the transformed sentence, the object of the given sentence does not come in the place of the subject of the given sentence, and 'be' cannot be used here respectively.
The correct answer is C)You are expected to complete this work before sunset.