Final answer:
The chemical that causes vasodilation during inflammation is histamine, which is released by mast cells and increases blood vessel diameter and permeability.
Step-by-step explanation:
The chemical of inflammation that causes vasodilation is histamine. Histamine is released by mast cells in response to tissue injury and plays a crucial role in the inflammatory process. Vasodilation is the widening of blood vessels, which increases blood flow to the affected area, resulting in redness and heat. This response also facilitates the arrival of white blood cells to the site of inflammation. Furthermore, histamine increases the permeability of blood vessels, leading to leakage of plasma and the subsequent swelling or edema associated with inflammation.