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
Serum marker after Hepatitis B vaccination ? 
Select and explain. 
A. Anti-HBsAg, B. Anti-HBeAg, C. Anti-HBcAg, D. HBsAg
A: Anti-HBsAg
Answer: A: Anti-HBsAg 
Explanation: Ans. is 'a' i.e., Anti-HBsAg