This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'The normal ratio of CD4to CD8 is \nSelect and explain. \nA. 1:01, B. 2:01, C. 8:01, D. 10:01', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref Robbins 9/e p190-191 A normal CD4/CD8 ratio is 2.0, with CD4lymphocytes equal to or greater than 400/mm3 and CD8 lymphocytes equal to 200 to 800/mm3. If your ratio is higher than 2, it means your immune system is strong and you may not have HIV. If your ratio is less than 1, you may have: HIV.', 'role': 'assistant'}]