The correct answer is: B. By whom are you taught English?
This is because the question is asking about the person who is currently teaching you English. The other options are not correct because they are either asking about the person who taught you English in the past (A), the person who will teach you English in the future (D), or they are not asking about a person at all (C).
Option A, “By whom were you taught English?” is asking about the person who taught you English in the past. This is not the same person who is currently teaching you English, so this option is not correct.
Option C, “English is taught by whom?” is not asking about a person at all. It is asking about the general concept of who teaches English. This option is not correct because the question is specifically asking about the person who is currently teaching you English.
Option D, “By whom will you be taught English?” is asking about the person who will teach you English in the future. This is not the same person who is currently teaching you English, so this option is not correct.
Therefore, the correct answer is: B. By whom are you taught English?