Final answer:
The priority action of the nurse is to assess a client who experiences unilateral calf pain when ambulating.
Step-by-step explanation:
The priority action of the nurse among the given options would be B) Assessing a client who experiences unilateral calf pain when ambulating.
This is because unilateral calf pain when ambulating could be a sign of deep vein thrombosis (DVT), a potentially serious condition that requires immediate intervention. Assessing the client would involve checking for other signs and symptoms of DVT, such as swelling, warmth, redness, and tenderness in the affected leg. The nurse may also consider ordering diagnostic tests, such as a Doppler ultrasound, to confirm the diagnosis.
While the other actions mentioned in the options are important, assessing a client experiencing unilateral calf pain takes priority due to the potential complications and risks associated with DVT.