This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sex-Hormone, Subject name: Pharmacology
[{'content': 'Erythropoietin is inhibited by - \nSelect and explain. \nA. Estrogen, B. Progesterone, C. Thyroxine, D. Testosterone', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Estrogen o Estrogen antagonizes the erythropoietin-augmenting effect of placental lactogen. It inhibits utilization of erythropoietin by the marrow stem cell, and also impairs its production.", 'role': 'assistant'}]