Which cell population of WBCs migrate to sites of injury and cross the capillary wall to accumulate within damaged tissues, where they discharge their granules into the interstitial fluids?

The correct answer is - Basophils

Explanation:

Basophils are one of the granulocytes of WBC. The basophils move to site of damaged tissue. They cross the capillary endothelium and gathred in the damaged tissues. They discharge their granules into the interstitial fluids.

The granules which is secreted by basophils includes histamine, heparin, and serotonin. The histamine dilates blood vessels, the heparin prevents blood clotting.

These chemicals into the interstitial fluids enhances the inflammation initiated by mast cells.