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: Surgery
[{'content': 'Erysipelas is caused by - \nSelect and explain. \nA. Staph aureus, B. Staph albus, C. Strep pyogenes, D. Hemophilus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Erysipelas\n\nis due to S. pyogenes and\nis characterized by an abrupt onset of fiery-red swelling of the face or extremities.\nthe distinctive features of erysipelas are well-defined indurated margins, particularly along the nasolabial fold; rapid progression; and intense pain.\nextension to deeper soft tissues is rare.\ntreatment with penicillin is effective', 'role': 'assistant'}]