This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammation & Repair, Subject name: Pathology
Which arachidonic acid metabolite is vasoconstrictor? 
Select and explain. 
A. TXA2, B. PGI2, C. PGD2, D. PGE2
A: TXA2
Answer: A: TXA2 
Explanation: Ans. is 'a' i.e., TXA2