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
EI Tor vibrio may be differentiated from classical vibrio by fact that EI Tor vibrio- 
Select and explain. 
A. Agglutinate chicken and sheep erythrocytess, B. Resistant to classical phage IV, C. Resistant to polymyxin B-50 unit disc, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: 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