This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Paul Bunnel antibodies are reactive in all except - \nSelect and explain. \nA. Ox, B. Sheep, C. Dog, D. Horse', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Paul Bunnell antibodies agglutinate sheep erythrocyte, horse and dog REF:ANANTHANARYANAN TEXTBOOK OF MICROBIOLOGY 9EDITION PGNO.476', 'role': 'assistant'}]