Which term describes the body's protective response to injury or infection, causing redness, heat, swelling, and pain?

• A. Edema
• B. Necrosis
• C. Ischemia
• D. Inflammation

Answer: (D)

Inflammation is the body's protective response to injury or infection. It brings immune cells and blood flow to the area to fight pathogens and start repair. The redness and heat come from increased blood flow, while swelling results from fluid leaking out of vessels, and pain can arise from chemical signals that sensitize nerves. Edema is swelling that happens during inflammation but isn’t the whole process itself. Necrosis is tissue death, and ischemia is reduced blood supply; neither captures the full protective response described by inflammation. So, the term described by those signs is inflammation.