This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Physiology
[{'content': 'Prostaglandin was discovered from \nSelect and explain. \nA. Tear, B. Saliva, C. Seminal fluid, D. Blood', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Prostaglandins were believed to be pa of the prostatic secretions, and eventually were discovered to be produced by the seminal vesicles. ... The biochemists Sune K. Bergstrom, Bengt I. Samuelsson and John R. Vane jointly received the 1982 Nobel Prize in Physiology or Medicine for their research on prostaglandins. Ref: guyton and hall textbook of medical physiology 12 edition', 'role': 'assistant'}]