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: Dental
[{'content': 'Impetigo contageosa most commonly due to – \nSelect and explain. \nA. Group B streptococcus, B. Staphylococci, C. Moniliasis, D. Streptococcus viridans', 'role': 'user'}, {'content': "Answer: B \nExplanation: Impetigo contagiosa is caused most often by staph aureus and in some cases by group 'A' streptococci.", 'role': 'assistant'}]