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: Pharmacology
[{'content': 'One of the following drugs does not cause thrombocytopenia: \nSelect and explain. \nA. Heparin, B. Phenobarbitone, C. Quinine, D. Thiazide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Phenobarbitone', 'role': 'assistant'}]