Answer: Option A. "inflammatory response"
Step-by-step explanation:
Inflammation can be defined as a biological response by our immune system which can be triggered by several factors, such as damaged cells, toxic compounds, and pathogens.
When a pathogen attacks, an inflammatory response takes place, which results in an increase in blood flow to the infected area. Then the blood vessels in that area expand, and white blood cells releases from those vessels to recover the infected tissue. The white blood cells, also called phagocyte destroy or engulf the bacteria. During inflammatory response, the infected area often becomes swollen, red and painful.
Thus, inflammatory response is the correct option.