This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of health and disease, Subject name: Social & Preventive Medicine
[{'content': '"Bullneck" appearance is a characteristic feature seen in \nSelect and explain. \nA. Epidermolysis bullosa, B. Severe Diphtheria, C. Epidemic Parotiditis, D. Acute Epiglottitis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Regional lymphadenopathy in diphtheria causes a brawny thickening /swelling all around the neck, giving a \'bull neck" appearance Ref : Park 23rd edition Pgno : 161', 'role': 'assistant'}]