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': 'Which of the following hormones is mainly responsible for skeletal maturation of long bones during pubey? \nSelect and explain. \nA. Testosterone, B. Estrogen, C. Growth hormone, D. Testosterone/estrogen ratio', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Estrogen promotes bone maturation and closure of epiphyseal plates in long bones. It conserves bone mass by suppressing bone turnover and maintaining balanced rates of bone formation and bone resorption. Estrogen affects the generation, lifespan, and functional activity of both osteoclasts and osteoblasts. It promotes synthesis of osteoprotegerin, decreases osteoclast formation and activity, and increases osteoclast apoptosis. Ref: Molina P.E. (2013). Chapter 9. Female Reproductive System. In P.E. Molina (Ed), Endocrine Physiology, 4e.', 'role': 'assistant'}]