This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'EI Tor vibrio may be differentiated from classical vibrio by fact that EI Tor vibrio- \nSelect and explain. \nA. Agglutinate chicken and sheep erythrocytess, B. Resistant to classical phage IV, C. Resistant to polymyxin B-50 unit disc, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: El Tor vibrios Agglutinate chicken and sheep erythrocytes. Resistant to classical phage IV Resistant to polymixin B-50-unit disc, and The VP reaction and haemolytic test do not give consistent results. Ref:PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition , Page 229', 'role': 'assistant'}]