This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
Heavy smoker for elective hernia repair, smoking should be stopped before how much period? 
Select and explain. 
A. 4 days, B. 10 days, C. 3-4 weeks, D. 6-8 weeks
D: 6-8 weeks
Answer: D: 6-8 weeks 
Explanation: Ans. is 'd' i.e., 6-8 weeksRef: Postgraduate anaesthesia p. 786'Limited prospective data suggest that cessation for at least 6-8 weeks preoperative is necessary to decrease the incidence of pulmonary complication."