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': 'Acantholysis is characteristic of – \nSelect and explain. \nA. Pemphigus vulgaris, B. Pemphigoid, C. Erythema multoforme, D. Dermatitis herpetifonnis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Histologically the common denominator in all forms of pemphigus is acantholysis.', 'role': 'assistant'}]