An older adult male reporting abdominal pain is admitted to the hospital from a long-term care facility. It has been 7 days since his last bowel movement, his abdomen is distended, and he just vomited 150 mL of dark brown emesis. In which order should the nurse implement these interventions? (Arrange with the highest priority intervention on top, and lowest priority intervention on bottom.)

A. Elevate the head of the bed. This intervention is the highest priority to prevent aspiration and improve the client's comfort and breathing. B. Complete focused assessment. A thorough assessment is necessary to gather more information about the client's condition and guide further interventions. C. Send emesis sample to the lab. This helps in diagnosing the underlying cause of the dark brown emesis, which could indicate a serious gastrointestinal issue. D. Offer PRN pain medication. Pain management is important but should be done after addressing immediate safety concerns and gathering sufficient assessment data.