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 of the following statements about carbohydrate antigen are true, EXCEPT: 
Select and explain. 
A. It has lower immunogenicity, B. Memory response is seen, C. Cause polyclonal B cell stimulation, D. Does not require stimulation by T cells
B: Memory response is seen
Answer: B: Memory response is seen 
Explanation: Carbohydrate C -Ag is found in the cell wall of streptococcus pneumoniae. It is independent of T cell response, so memory response is present in the carbohydrate C - Ag. Polysaccharides (carbohydrates) are less immunogenic than protein antigens, but are more antigenic than lipids & nucleic acids. Carbohydrate (Polysaccharide) antigens are T- cell independent. Their immune response does not require activation of T-cells. These antigens directly stimulate B-cells without processing by antigen presenting cells. There is no memory response. Ref: Ananthanarayanan & Paniker's textbook of microbiology 7th ed pg 81.