Which one of the following statements best describes the role of B cells and T cells in the human body ?

B cells and T cells are the fundamental components of the adaptive immune system that recognize and neutralize specific pathogens, such as bacteria and viruses, to protect the body from infectious diseases. While these cells are involved in allergic reactions (Option A), this is often a hypersensitive or maladaptive response rather than their primary biological purpose of defense. The core concept tested is the functional role of lymphocytes in providing acquired immunity against harmful microorganisms.