Which statement about B-Lymphocytes is true?

• A. They are T-Cells.
• B. They function as phagocytes.
• C. They produce antibodies.
• D. They play a major role in cell-mediated immunity.

Answer: (C)

B-lymphocytes are the scouts of humoral immunity. Their main role is to produce antibodies. Each B cell has a receptor specific for an antigen, and when activated—often with help from helper T cells—the B cell becomes a plasma cell that churns out large amounts of antibodies. Those antibodies circulate in the blood and lymph, neutralizing pathogens, tagging them for attack by other immune cells, and helping activate the complement system. This is why the true statement is that B-lymphocytes produce antibodies. They are not T cells, they do not function primarily as phagocytes (that job belongs to cells like macrophages and neutrophils), and the major driver of cell-mediated immunity is T lymphocytes rather than B lymphocytes.