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: Medicine
[{'content': "Early manifestation of a patient infected with HIV virus is: \nSelect and explain. \nA. Elevation of p16, B. Unexplained fear and weight loss, C. Kaposi's sarcoma, D. Hairy cell leukoplakia", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]