Final answer:
Neutrophils are the first leukocytes called to infected areas and are responsible for phagocytosis and the early pro-inflammatory response.
Step-by-step explanation:
The first leukocyte called to infected areas in mass is C) Neutrophils. These are phagocytic cells that are part of the innate immune system and act quickly to fight off infections. They are responsible for the early stages of the inflammatory response, engulfing and digesting pathogens through phagocytosis and releasing pro-inflammatory cytokines that promote inflammation. Neutrophils are considered the most abundant leukocytes in the immune system and are the body's first responders to infection. They contain granules with enzymes that are used to kill pathogens, and these cells often die after phagocytizing a few pathogens, underscoring their role as a frontline defense mechanism.