—I don't know ______ to do with this letter. May I give it to our teacher?

—I don't think so. You'd better not do it like this. [ ]

A. what

B. where

C. how

D. why

麻醉、精神类戒毒药品严格按照专人、专柜、专账、专册、专用处方“五专”要求管理。