【单选题】

If I had taken the doctor's advice and rested for a few days, I should have completely recovered by now.
A．如果我能听医生的话，休息几日，早就应该完全康复了。

B．只要我肯听医生的建议，休息几天，就一定能够完全康复。
C．假如我听医生的劝告，歇息几天，我应该现在就已经完全康复。
D．要是我听了医生的劝告，休息几天，现在就能完全康复了。