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: ENT
[{'content': "Ludwig's angina is characterized by all the following except - \nSelect and explain. \nA. Cellulitis of the floor of the mouth, B. Caused by anaerobic organisms, C. Aphthous ulcers in the pharynx, D. Infection spreads to retropharyngeal space", 'role': 'user'}, {'content': "Answer: C \nExplanation: Since most cases of Ludwig's angina are related to a dental cause, it is not surprising that the bacterial cultures mirror the oral flora.\nThese infections are almost always the result of mixed flora, involving both aerobes and anaerobes. The most commonly reported aerobes are alpha-hemolytic streptococci, followed by staphylococcus. The anaerobic bacteria are peptostreptococcus, Bacteroides, Veillonella and Spirochaeta.\nSubmandibular space infection may also spread posteriorly to the carotid sheath or retropharyngeal space or both, by crossing the lateral pharyngeal space.", 'role': 'assistant'}]