Final answer:
While positioning an immobile patient, the nurse should aim to maintain proper body alignment and comfort, reposition at least every two hours, and customize the positioning to the patient's specific health needs.
Step-by-step explanation:
When positioning an immobile patient, the nurse should implement actions that maximize the patient's comfort, maintain proper body alignment, prevent complications such as pressure sores, and support physiological functioning. Given the options, visualization of a person's standing position to achieve a similar body alignment while lying down (Option b) provides a baseline for proper positioning. However, care must be taken to customize the position to the patient's specific needs and medical condition. Careful attention to repositioning should be exercised; generally, patients should be repositioned at least every two hours, not every four hours, to prevent pressure ulcers and other complications of immobility. Also, placing a patient solely on their back is not always advisable, as different positions may be needed to prevent pressure sores, aid in breathing, and address other health concerns.