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
True statement about Widal test in typhoid is? 
Select and explain. 
A. 0-antigen titre remains positive for several months & reaction to it is rapid, B. H-antigen titre remains positive for several months & reaction to it is rapid, C. Both remain positive for several months & reaction to both is rapid, D. None
B: H-antigen titre remains positive for several months & reaction to it is rapid
Answer: B: H-antigen titre remains positive for several months & reaction to it is rapid 
Explanation: Ans. is 'b' i.e., H-antigen titre remains positive for several months and reaction to it is rapid