Final answer:
The nurse should assess the client who is 12 hr postoperative following abdominal surgery and has an absent bowel first, as this could indicate a potential complication that requires immediate intervention.
Step-by-step explanation:
The nurse should plan to assess the client who is 12 hr postoperative following abdominal surgery and has an absent bowel. This is because absent bowel sounds could indicate a potential complication such as bowel obstruction or bowel perforation, which require immediate intervention. The other options may also require assessment and intervention, but the absent bowel sounds are the most urgent and potentially life-threatening.