Which of the following best describes steps that take place during a humoral immune response?

t cells divide into t cells and cytotoxic t cells to fight infectious agents.

cytotoxic t cells destroy pathogens that are detected by memory t cells.

memory b cells divide and produce plasma cells that engulf and destroy pathogens.

b cells bind to an antigen and produce plasma cells and memory b cells.

Lets remember that humoral immune response is antibody-mediated immune system. During this response, B cell is activated to become plasma cell and memory cell. The plasma cell produces antibody specific to the antigen. The memory cell is used for subsequent infection by same antigen because they 'keep memory' as their name suggest. So the correct answer would be B cells bind to an antigen and produce plasma cells and memory B cells.