This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Which of the following causes vasoconstriction in all vascular beds 
Select and explain. 
A. PGE2, B. PGF 2a, C. PGI2, D. TXA2
D: TXA2
Answer: D: TXA2 
Explanation: Answer- D. TXA2COX pathway is involved in the synthesis of prostaglandins and Thromoxane A2.Endothelium contains PGI2 synthase and thus forms PGI2Platelets contain TXA2 synthase and therefore synthesize TXA2Blood vessels- Thromboxane A2 (TXA2)