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: Microbiology
Infectivity of HBsAg is best/commonly diagnosed by- 
Select and explain. 
A. HBeAg, B. HbsAg, C. HBV DNA, D. Anti HBs Ag
A: HBeAg
Answer: A: HBeAg 
Explanation: None