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: Pathology
[{'content': 'Screening for following viral infections in blood donor is compulsory: \nSelect and explain. \nA. HIV, B. HBV, C. HCV, D. All of these', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Screening of all blood donations should be mandatory for the following infections and using the following markers:\n\nHIV-1 and HIV-2:\xa0Screening for either a combination of HIV antigen-antibody or HIV antibodies.\nHepatitis B:\xa0Screening for hepatitis B surface antigen (HBsAg).\nHepatitis C: Screening for either a combination of HCV antigen-antibody or HCV antibodies.\nSyphilis (Treponema pallidum):\xa0Screening for specific treponemal antibodies.', 'role': 'assistant'}]