This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Vasoconstricting mediator is - 
Select and explain. 
A. Prostacyclin, B. Thromboxane-A2, C. PGD2, D. Lipoxins
B: Thromboxane-A2
Answer: B: Thromboxane-A2 
Explanation: Robbins basic pathology 9th edition page no 46, Thromboxane A2 is a potent vasoconstrictor Lipoxins are arachidonic acid metabolite which has anti-inflammatory action. PGF2a is a vasoconstrictor whereas PGD2 and PGE2 are vasodilators