The answer is A.chemicals called cytokines are secreted from helper t cells to signal production of antibodies by b cells.
-Some cells present parts of an pathogen that they thing should be eliminated.This is, for example, what dendritic cells do.
-T helper cells recognize those parts and starts to produce cytokines.
- Those cytokines secreted will stimulate other cells to produce more or to activate.
- B cells, which produce antibodies, will bestimulated by cytokines released by T helper cells.