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 about secondary immune response is -a) Long latent periodb) Usually of low titrec) Antibodies appear in short timed) Persist for long 
Select and explain. 
A. ab, B. cd, C. bd, D. ac
B: cd
Answer: B: cd 
Explanation: None