The practical nurse (PN) enters the room of a client who underwent a mastectomy eight hours ago. The PN observes the unlicensed assistive personnel (UAP) preparing to measure the client's blood pressure using an automated blood pressure device on the client's operative side. Which action should the PN implement?

A. Reviewing the blood pressure measurement is not the primary concern here; the issue is that the UAP is using the incorrect arm for the measurement. B. The blood pressure should be measured on the non-operative side. Measuring on the operative side can cause discomfort, potential injury, or interfere with the healing process. C. Elevating the arm after recording the blood pressure is not a standard requirement post-mastectomy. The immediate concern is the proper measurement site for the blood pressure. D. A manual blood pressure cuff is not required for accuracy in this situation; the key issue is to use the non-operative arm for measurement.