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
A 60-year-old man with no significant past medical history is scheduled for elective cholecystectomy. He has been taking aspirin daily. Preoperative recommendations should include which of the following? 
Select and explain. 
A. Determination of prothrombin time (PT), B. Estimation of platelet count, C. Discontinuation of aspirin 2 days before surgery, D. Discontinuation of aspirin at least 1 week before surgery
D: Discontinuation of aspirin at least 1 week before surgery
Answer: D: Discontinuation of aspirin at least 1 week before surgery 
Explanation: Discontinuation of aspirin at least 1 week before surgery. Aspirin inactivates platelet cyclo-oxygenase and thus inhibits platelet aggregation. The effect of aspirin is irreversible and lasts for the entire life span of the platelets. Therefore, aspirin should be discontinued for at least 1 week before surgery.