She agreed , of course , and now , found herself sitting at the front of an empty classroom , while glittery bits filled her lesson plan . Class had to go on , though . The chalkboard would suffice as a teaching medium , and her brilliant intellect would wow and amaze ! There would be no problems today .
According to the above context, answer the following question.
What does the subject use to instruct the students ?


None of the above choices .