The unlicensed assistive personnel (UAP) reports that a client's blood pressure cannot be measured in the arms because the client has casts on both arms and is unable to be measured in the legs because the client is in the supine position. Which action should the nurse implement?

A. Advise the UAP to document the last blood pressure obtained on the client's graphic sheet: Documenting a previous reading does not reflect the client’s current condition and can be misleading in decision-making. Vital signs should be based on real-time assessment. B. Demonstrate how to palpate the popliteal pulse with the client supine and the knee flexed: The popliteal site is appropriate for measuring blood pressure when the arms are inaccessible. Flexing the knee while the client is supine allows better access to the artery and enables accurate assessment of blood pressure in this situation. C. Document why the blood pressure cannot be accurately measured at the present time: While documentation is necessary if no alternative is available, the nurse must first exhaust appropriate options for obtaining a blood pressure before choosing to omit it. D. Estimate the blood pressure by assessing the pulse volume of the client's radial pulses: Pulse volume gives a very rough estimate of perfusion but does not provide an accurate or objective blood pressure measurement. This method lacks precision.