This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NSAIDs, Gout and Rheumatoid Ahritis, Subject name: Pharmacology
Aspirin in low doses produces long lasting inhibition of platelet cyclooxygenase because: 
Select and explain. 
A. Platelet contain low quantity of COX, B. Platelets cannot synthesize fresh COX molecules, C. Platelets bind aspirin with high affinity, D. Platelet COX is inducible
B: Platelets cannot synthesize fresh COX molecules
Answer: B: Platelets cannot synthesize fresh COX molecules 
Explanation: Aspirin in low doses irreversibly inhibits COX enzyme in platelets and the endothelium. Platelets lack nucleus and thus cannot regenerate COX whereas endothelium can synthesize fresh enzyme. Net effect of this process is the inhibition of platelet cox and thus, TXA2 synthesis. Low TXA2 level results in the anti-aggregation of platelets.