A nurse is caring for a client who is postoperative following a total hip arthroplasty. Which of the following actions should the nurse take to prevent dislocation?

The correct answer is B: Place a pillow between the client's legs. Placing a pillow between the client's legs helps maintain proper alignment of the hip joint, preventing adduction, which can lead to hip dislocation. Adducting the legs (choice A) increases the risk of dislocation. Flexing the hip to 120 degrees (choice C) and sitting in a low chair (choice D) can also increase the risk of dislocation as they can put stress on the hip joint. Placing a pillow between the legs is a simple and effective way to maintain proper positioning and prevent dislocation.