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': 'All causes erythema multiforme except – \nSelect and explain. \nA. HSV, B. Drugs, C. Idiopathic, D. HPV', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Idiopathic erythema multiforme is the most common cause of EM.\nHerpes simplex is the most important infectious cause of EM.\nDrugs, like NSAIDs & phenytoin can cause EM.', 'role': 'assistant'}]