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: Medicine
[{'content': 'Which of the following is seen in secondary hyperparathyroidism is \nSelect and explain. \nA. Chronic hypercalcaemia, B. Chronic hypocalcaemia, C. Chronic hypomagnaesemia, D. Chronic hypermagnaesemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]