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
Screening for following viral infections in blood donor is compulsory: 
Select and explain. 
A. HIV, B. HBV, C. HCV, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Screening of all blood donations should be mandatory for the following infections and using the following markers:

HIV-1 and HIV-2: Screening for either a combination of HIV antigen-antibody or HIV antibodies.
Hepatitis B: Screening for hepatitis B surface antigen (HBsAg).
Hepatitis C: Screening for either a combination of HCV antigen-antibody or HCV antibodies.
Syphilis (Treponema pallidum): Screening for specific treponemal antibodies.