Question

please solve fast""""""""​

Answer 1

Answer:

Step-by-step explanation:

Mast cells are a type of white blood cells. It has granules which are rich in histamine and heparin. Histamine is a vasodilator which dilates post-capillary venules, activates the endothelium, and increases blood vessel permeability.

Heparin is an anticoagulant which is used to cure thrombosis. Serotonin is a vasoconstrictor which is secreted due to degranulation of mast cells. When the platelets bind to a clot, they release serotonin, where it serves as a vasoconstrictor and helps to regulate hemostasis and blood clotting.

So, the correct answer is option D.