Which statement best describes innate immunity?

• A. Antibodies are a primary component
• B. T cells are the main effector in innate immunity
• C. B cells and antibodies mediate innate responses
• D. Phagocytes, complement, and inflammatory mediators are included

Answer: (D)

Innate immunity is the body's immediate, non-specific defense against pathogens. It uses fast-acting cellular and chemical defenses that don’t require prior exposure. Phagocytes such as neutrophils and macrophages grab and digest microbes. The complement system helps mark invaders for destruction and can directly lyse some pathogens. Inflammatory mediators like histamine and cytokines trigger tissue changes that bring more immune cells to the site of infection.

Antibodies and the B and T cells are part of the adaptive immune system, which is specific and develops after exposure, with the ability to remember pathogens for faster responses in the future. So the statement that includes phagocytes, complement, and inflammatory mediators captures the innate components, while the others describe adaptive features.