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: Physiology
[{'content': 'a-receptor of estrogens are? \nSelect and explain. \nA. Membrane receptors in breast, B. Nuclear receptors in breast, C. Membrane receptors in ovaries, D. Nuclear receptors in ovaries', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Nuclear receptors in breast(Ref: Principles of medical physiologlt p. 777).Estrogen binds to nuclear receptors --> Estrogen receptors (ERs)", 'role': 'assistant'}]