问题
单项选择题
After 5 days of hospitalization, the client who is receiving morphine sulfate for pain control asks for more pain medication with increasing frequency and exhibits increased anxiety and restlessness. His physical condition is stable. What is the probable cause of his behavior（）
A. His morphine dosage is too high.
B. His coping mechanisms are exhausted.
C. He is becoming addicted to the narcotic.
D. He has developed tolerance to his narcotic dosage.
答案
参考答案：D
解析：
Tolerance to a regular narcotic dose can develop with frequent use. The client experiences increased discomfort, asks for medication more frequently, and exhibits anxious and restless behavior, which are often misinterpreted as indicative of developing dependence or addiction.