Question

how does fever indicate that your bodys immune system is doing its job?
fever increases red blood cell production.
fever raises the bodys temperature to destroy harmful substances.
fever triggers inflammation.
fever causes the secretion of hormones that fight harmful substances.

Explanation:

• Analyze Option 1: Red blood cells are mainly for oxygen transport, and fever doesn't increase their production. So this is incorrect.
• Analyze Option 2: Many harmful substances (like bacteria, viruses) have an optimal temperature range for survival. Raising the body's temperature through fever can inhibit or destroy them, which is part of the immune system's response. This makes sense.
• Analyze Option 3: Inflammation is often a response to injury or infection, but fever itself doesn't trigger inflammation. Inflammation can sometimes accompany fever due to the immune response, but the causation here is wrong.
• Analyze Option 4: Fever is a result of the immune response (like from cytokines), not the cause of hormone secretion to fight harmful substances. Hormone secretion for immunity is part of the immune system's activation, but fever is a secondary effect, not the cause of that hormone secretion.

Answer:

B. Fever raises the body’s temperature to destroy harmful substances.