Q.B - lymphocytes are activated by :

B-lymphocytes are activated by binding to a specific antigen, which drives their proliferation into antibody-secreting plasma cells and memory cells.

B-lymphocytes carry membrane-bound antibody (immunoglobulin) receptors on their surface that are specific to a particular antigen. When that antigen binds the receptor (often with helper-T-cell co-stimulation), the B-cell is activated, proliferates by clonal expansion, and differentiates into plasma cells (which secrete large amounts of soluble antibody) and memory B-cells. Interferon (a) is an antiviral signalling protein, not the trigger for B-cell activation. Antibiotics (b) are drugs that kill/inhibit microbes and have no ro …