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
All are true about widal test except 
Select and explain. 
A. Base lines differ depending on the endemicity of the disease, B. O antibodies last longer and hence is not indicative of recent infection, C. H antigen cannot differentiate between subtypes, D. High titre value in a single widal test is not confirmative
B: O antibodies last longer and hence is not indicative of recent infection
Answer: B: O antibodies last longer and hence is not indicative of recent infection 
Explanation: None