【单选题】

The client is taking medication to control his cancer pain. Which of the following statements indicates that the client needs further instruction

A、"I should take my medication around-the-clock to control my pain. "
B、"I should skip doses periodically so I don’t get hooked on my drugs. "
C、"It is okay to take my pain medication even if I am not having any pain. "
D、"I should contact the oncology nurse if my pain is not effectively controlleD、"