Final answer:
The nurse should evaluate the effectiveness of Alexander's pressure-reducing gel chair cushion to ensure it provides the necessary relief and comfort.
Step-by-step explanation:
If Alexander has a pressure-reducing gel chair cushion for his wheelchair, the nurse should take the following action: C. Evaluate the effectiveness of the cushion. This is because it is essential to ensure that the cushion is providing the necessary pressure relief to prevent pressure ulcers and improve comfort.
The nurse should monitor the skin integrity of areas in contact with the cushion, ask Alexander about his comfort level, and observe for any signs that the cushion is helping reduce pressure appropriately. If the cushion is not effective, adjustments or alternatives may need to be considered.