The complement system functions as a defense mechanism against microbial infections, specifically bacteria, by initiating a cascade of reactions resulting in the destruction of foreign invaders. Which of the following statements best describes the mechanism of destruction of bacteria by the complement system:

• A. Formation of antibodies that bind to the bacteria and enhance their phagocytosis.
• B. Opsonization of bacteria by C3b, which can covalently bind to the surface of bacteria and enhance their phagocytosis.
• C. Release of cytotoxic substances to kill the bacteria directly in a way similar to cytotoxic T-cell mediated destruction of pathogens.
• D. Membrane attack complex formation, which consists of complement proteins C5b, C6, C7, C8, and multiple copies of C9, causing the formation of a pore-like structure in the bacterial membrane, disrupting the bacterial cell wall and membrane.
• E. Both (b) and (d).
• F. All of the above.

Answer: (E)