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: Pathology
[{'content': 'Anticoagulant of choice for ESR by Wintrobes method -a)  Citrateb)  Heparinc)  Oxalated)  EDTA \nSelect and explain. \nA. ab, B. cd, C. bd, D. ac', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Anticoagulant of choice for ESR by \xa0\n\tWintrobes method\xa0\xa0→ Double oxalate & EDTA\n\tWestergren method\xa0→ Sodium citrate', 'role': 'assistant'}]