A nurse is teaching a client who had a total knee arthroplasty about self-administering morphine via a patient-controlled analgesia (PCA) infusion device. Which of the following client statements indicates an understanding of the teaching?

"I should tell the nurse if I can't control my pain with this device."

"I should only use the device when it's absolutely necessary."

"I'll be careful about pushing the button, so I don't overdose."

"I will ask my family to push the dose button when I am asleep."