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
True about thromboxane A2: 
A) Formed by platelets
B) Formed from PGG2/PGH2
C) Prothrombogenic
D) Vasoconstricter
E) Vasodilator 
Select and explain. 
A. ABC, B. ABCDE, C. ABCD, D. ACB
C: ABCD
Answer: C: ABCD 
Explanation: None