Answer:
The correct answer is A.
Explanation:
B-lympocytes participate in antibody-mediated immunity (also called humoral immunity)- They activate in the lymph nodes and/or in lymphatic organs when they are exposed to an antigen.
Also T-lymphocytes participate in cell-mediated immunity, they release different types of cytokines when they are exposed to an antigen. Macrophages and natural killer cells also participate in this type of immunity.
