Answer:
(A). the inflammatory response 
Step-by-step explanation:
Inflammation can be defined as a nonspecific immune response that occurs due to any injury or infection to tissues. It leads to mobilization of inflammatory substances, such as histamines and phagocytic cells to the affected area and 
Inflammation triggers redness, swelling, and pain in affected area due to increased blood circulation and inflammatory substances. 
Thus, the correct answer is option (A).