Which statement about white blood cells is correct?

Which statement about white blood cells is correct?

• A. They defend against infection and disease
• B. They carry oxygen to working muscles
• C. They clot blood
• D. They regulate blood sugar

Answer: (A)

White blood cells are part of the immune system and their primary job is to defend the body against infection and disease. They identify and attack pathogens, engulf and destroy invaders, and produce antibodies to target specific threats. This immune function is what makes them the correct description. Oxygen transport is done by red blood cells, which carry hemoglobin-bound oxygen to muscles. Platelets are responsible for blood clotting to stop bleeding, not white blood cells. Regulation of blood sugar is controlled by hormones such as insulin, produced by the pancreas. So the statement that white blood cells defend against infection and disease best describes their role.

White blood cells are part of the immune system and their primary job is to defend the body against infection and disease. They identify and attack pathogens, engulf and destroy invaders, and produce antibodies to target specific threats. This immune function is what makes them the correct description. Oxygen transport is done by red blood cells, which carry hemoglobin-bound oxygen to muscles. Platelets are responsible for blood clotting to stop bleeding, not white blood cells. Regulation of blood sugar is controlled by hormones such as insulin, produced by the pancreas. So the statement that white blood cells defend against infection and disease best describes their role.