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': 'Pityriasis rosea  is caused by \nSelect and explain. \nA. Autoimmune etiology, B. HHV 3 & 4, C. HHV 4 & 5, D. HHV 6 & 7', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pitryiasis rosea is caused by HHV 7 > HHV 6', 'role': 'assistant'}]