Option A is the correct answer. The two kinds of grammatical voices are active and passive. The subject performs the action, and the object is the recipient in active sentences. The action is carried out by the object in the passive form. In the given sentence, 'Miss Mary' is the subject, and 'English' is the object. When this sentence is converted into a passive voice, the subject 'Miss Mary' becomes the object, and the object 'English' becomes the subject.