Answer: D) The student completed the test.
Explanation: passive voice is a form or set of forms of a verb in which the subject undergoes the action of the verb. Active voice is when the subject performs the action of the verb. In the given sentence we can see an example of passive voice, because the subject of the sentence (the test) is not performing the action of the verb (the student is the one who completed the test). So, to make this sentence more active we need to write it with "the student" as the subject: The student completed the test.