Questions: Following proliferation to form a clone, some B cells differentiate into B cells, which can rapidly respond to a future exposure to the same antigen.

The answer is: memory B cells.

Explanation: Following proliferation to form a clone, some B cells differentiate into memory B cells, which can rapidly respond to a future exposure to the same antigen. Memory B cells are a crucial component of the adaptive immune system. They are long-lived cells that "remember" the specific antigen that triggered their formation. Upon re-exposure to the same antigen, memory B cells can quickly mount a robust immune response, often more efficiently than the initial response, providing the body with long-term immunity.