Which of the Following Pain Medication Orders for a Client

Which of the following pain medication orders for a client with ovarian cancer would be most appropriate for the nurse to use to control a client's chronic pain?

A) Administer short-acting pain medication as needed.
B) Administer short-acting pain medication around the clock.
C) Administer long-acting pain medication when the client reports severe pain.
D) Administer long-acting pain medication around the clock.