This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
In the immediate postoperative period, the common cause of respiratory insufficiency could be because of the following except: 
Select and explain. 
A. Residual effect of muscle relaxant, B. Overdose of narcotic analgesic, C. Mild hypovolemia, D. Myocardial infarction
C: Mild hypovolemia
Answer: C: Mild hypovolemia 
Explanation: Ans. (c) Mild hypovolemia(Ref: Bailey 26/e p15)Immediate post op Dyspnea:* MI* Heart failure* Pulmonary embolism* Exacerbation of COPD/asthma