A Patient Is Taking Meperidine (Demerol)as Needed for Moderate to Severe

A patient is taking meperidine (Demerol) as needed for moderate to severe pain following an open appendectomy.The nurse assesses the following: current pain level 2,temperature 99°F,BP 130/76,respirations 10,lung sounds clear,abdomen soft and tender,bowel sounds present.Based on this assessment information,the priority nursing diagnosis is:

A) altered breathing pattern.
B) risk for altered body temperature.
C) risk for constipation.
D) pain.