A nurse is providing preoperative teaching about patient-controlled analgesia (PCA) to a client. Which of the following statements should the nurse include in the teaching?

"Continuous PCA infusion is designed to allow fluctuating plasma medication levels."

"You should push the button before physical activity to allow maximum pain control."

"You can adjust the amount of pain medication you receive by pushing on the keypad."

"The PCA will deliver a double dose of medication when you push the button twice."