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: Microbiology
[{'content': 'Most common biotype of S. aureus causing human infection ? \nSelect and explain. \nA. A, B. B, C. C, D. D', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., A Staphylococcus aureus has been classified into six biotypes : A, B, C, D, E and F. Most human pathogenic strains belong to biotype A.", 'role': 'assistant'}]