A 5-year-old boy presents with an infection caused by a polysaccharide-encapsulated bacterium. His immune system generates a weak antibody response to the polysaccharide antigen. This is an example of a response to which type of antigen?

• A. T-dependent antigen
• B. T-independent antigen
• C. Superantigen
• D. Autoantigen

Answer: (B)