A type of white blood cell made in the bone marrow that is part of the immune system; includes B lymphocytes and T lymphocytes.

• A. Neutrophils
• B. Monocytes
• C. Lymphocytes
• D. Eosinophils

Answer: (C)

Lymphocytes are the white blood cells responsible for adaptive immunity. They’re made in the bone marrow, and this group includes the B lymphocytes and T lymphocytes. B cells mature to produce antibodies that tag and neutralize invaders, while T cells coordinate the immune response and can directly attack infected cells. This combination of production in the bone marrow and the inclusion of B and T cells is what makes lymphocytes the best answer.

Other white blood cells, like neutrophils, monocytes, and eosinophils, serve different roles such as immediate phagocytosis, macrophage formation, or defense against parasites and allergies. They don’t encompass the B and T lymphocyte lineage, which is why the lymphocytes option fits best.