What Are the Two Main Functions of B Cells

What are the two main functions of B cells?

A) Activation of helper T cells and antibody production.
B) Activation of memory CD8⁺ T cells and antibody production.
C) Activation of naïve CD4⁺ T cells and memory CD8⁺ T cells.
D) Activation of memory CD4⁺ T cell and antibody production.
E) Activation of naïve CD4⁺ T cells and memory CD4⁺ T cells.