Although the complement cascade can be initiated by antibodies bound to the surface of a pathogen, complement activation is generally considered to be an innate immune response. This is because:

Correct Answer: A

Rationale: Alternative/lectin pathways use innate recognition molecules ; MAC , inflammation , and phagocytosis are outcomes, not the innate basis.

Correct Answer: C

Rationale: Innate immunity includes both external barriers (skin, secretions, mucous membranes) and internal defenses (inflammatory response), making both A and B correct.

Correct Answer: B

Rationale: Inflammation clears pathogens and starts tissue repair, a nonspecific process, unlike antibody production or cell-mediated responses (adaptive immunity).

Correct Answer: C

Rationale: Activated T cells (e.g., cytotoxic T cells) target intracellular pathogens, like viruses in infected cells, not extracellular pathogens or mediators.

Correct Answer: A

Rationale: Lymphocytes (B and T cells) are not phagocytic, focusing on adaptive immunity, unlike neutrophils, dendritic cells, and macrophages.