Final answer:
The client is at highest risk for altered oral mucous membranes due to having a nasogastric tube for 3 days.
Step-by-step explanation:
The client is at highest risk for 4. Altered oral mucous membranes.
Having a nasogastric tube for 3 days can cause dryness and irritation of the oral mucous membranes. This can lead to discomfort and an increased risk of infection.
It is important for the healthcare team to monitor and provide proper oral care to prevent complications.