A patient with a bacterial infection develops localized redness, swelling, heat, and pain. These cardinal signs of inflammation are primarily mediated by the local release of which of the following?

✓ Correct Answer: Option B

Histamine, released by mast cells, causes vasodilation and increased vascular permeability (redness, swelling). Prostaglandins mediate vasodilation, pain, and fever. Both contribute significantly to the cardinal signs of acute inflammation.