Select the sentence that uses correct capitalization

Part A: At the end of appointment, the Doctor said, "please exercise daily and eat healthy foods."


Part B: At the end of appointment, the doctor said, "Please exercise daily and eat healthy foods."


Part C: at the end of appointment, the Doctor said, "please exercise daily and eat healthy foods."


Part D: At the end of appointment, the Doctor said, "Please exercise daily and eat healthy foods."