Final answer:
B lymphocytes, also known as B cells, are made in the bone marrow. They are crucial white blood cells that produce antibodies for the immune system. Their development and maturation occur primarily in the bone marrow before they move on to other lymphatic organs.
Step-by-step explanation:
B lymphocytes, or B cells, are specialized white blood cells that are integral to the immune system. They are responsible for the production of antibodies that are involved in humoral immunity. The development and maturation of B cells begin in the bone marrow, which is the primary site for hematopoiesis (the production of blood cells). In the process of lymphocyte production, B cells undergo nearly all of their development in red bone marrow before they migrate to other parts of the immune system, like the spleen.
B cells receive their name from the fact that they mature in the bone marrow, distinguishing them from T cells, which mature in the thymus. Once matured, B cells can differentiate into plasma cells that secrete antibodies when activated. Therefore, B lymphocytes are made in the bone marrow (Option 2).