【单选题】

Doctor: It's the flu. Drink plenty of water and have a good rest.
Patient: Do I have to stay in bed I have piles of work to do at office.
Doctor: ______
A．Did you hear what I just said

B．You needn't go to the office.
C．It's OK if you have to work overtime.
D．I'm afraid you have to keep it off your mind for a week or so.