A nurse is providing preoperative teaching to a client about the administration of morphine via a PCA pump. Which of the following statements by the client indicates an understanding of the teaching?

Rationale: A. "Using this machine increases my risk of overdose.": PCA pumps are designed with safety features, including dose limits and lockout intervals, which reduce the risk of overdose. Understanding this helps the client recognize that PCA is a safe method for self-administered pain control when used correctly. B. “I can get pain medication any time as long as I press the button”: The client can only receive medication according to the programmed dose and lockout interval. Pressing the button repeatedly will not override the safety mechanism, so this reflects a misunderstanding of how PCA pumps function. C. "My partner can press my pain medication button for me if I am sleeping": PCA pumps are intended for self-administration only. Allowing someone else to press the button (a practice called “PCA by proxy”) can cause overdose and is unsafe, especially if the client is sleeping or sedated. D. "I will receive a limited amount of pain medication when I press the button.": PCA pumps deliver a preset dose with a lockout interval to prevent overdose. This statement shows the client understands the safety mechanisms in place, indicating correct comprehension of PCA use.