This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'The commonest organism causing cellulitis is \nSelect and explain. \nA. Streptococcus pyogenes, B. Streptococcus faecalis, C. Streptococcus viridans, D. Microaerophilic streptococci', 'role': 'user'}, {'content': "Answer: A \nExplanation: Streptococcus pyogenes causes a variety of suppurative infection of the skin, including infection of the wound or burns, with a predilection to produce cellulitis and lymphangitis. Streptococcal subcutaneous infection ranges from cellulitis to Necrotising fasciitis. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 215", 'role': 'assistant'}]