How does inflammation help the body fight off further infection?
Inflammation keeps harmful substances away from healthy cells.
Inflammation triggers the production of white blood cells.
Inflammation drops the pH of blood.
Inflammation raises the pH of blood.

Inflammation helps an organism's body fight off a further infection because this inflammation keeps harmful substances away from healthy cells (first option).

Explanation:

Harmful agents are chemical substances or biological agents -such as bacteria, viruses, parasites or pathogenic fungi- which can cause tissue damage and break the organic balance.

Inflammation is a non-specific and innate immune process that occurs in tissues with abundant blood supply, in response to a harmful agent and caused by substances called inflammatory agents.

The inflammatory response in the body consists of the release of some substances that produce an increase in the blood supply that leads to an increase in volume, flushing and heat in the affected tissue, which is intended to isolate the harmful agents -keeping them away from healthy cells- and initiate the process of repairing a damaged tissue.

Learn more:

Cardinal signs of inflammation link