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
[{'content': 'Thromboxane A2- \nSelect and explain. \nA. Formed by platelets, B. Formed from PGG2\\/PGH2, C. Prothrombotic, D. Vasoconstrictor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Robbins basic pathology 9th edition, page no:46 Platelets contain the enzyme thromboxane synthase producing thromboxane A2.', 'role': 'assistant'}]