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': 'Impetigo contagiosa is caused by \nSelect and explain. \nA. Group A beta hemolytic streptococci, B. Staphylococcus, C. Hemophilus influenzae, D. Pseudomonas', 'role': 'user'}, {'content': "Answer: A \nExplanation: Impetigo is caused by Streptococcus pyogenes belonging to a limited number of serotypes, usually high numbered M types, instead of the lower numbered M types which cause throat infection. Impetigo and streptococcal infection of scabies is the main cause of acute glomerulonephritis in children in tropics. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 215", 'role': 'assistant'}]