Question

multiple choice question
what does the bodys second line of defense against pathogens consist of?

antimicrobial proteins, leukocytes, and macrophages
specific defenses
external barriers

Explanation:

The body's first line of defense is external barriers (like skin), the third is specific defenses (adaptive immunity). The second line is non - specific internal defenses including antimicrobial proteins, leukocytes (white blood cells), and macrophages (a type of leukocyte) that act against pathogens. "Specific defenses" are the third line, and "External barriers" are the first line.

Answer:

A. Antimicrobial proteins, leukocytes, and macrophages