This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology and Rheumatology, Subject name: Medicine
[{'content': 'Which of the following clinical findings is characteristic of both osteomalacia and rickets? \nSelect and explain. \nA. frontal bossing in the skull, B. muscle weakness, C. prominent costochondral junctions, D. defects in tooth enamel', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Muscle weakness is common in both rickets and osteomalacia, and proximal leg muscles are particularly involved. The combination of leg deformity and muscle weakness in rickets can result in an inability to walk. The presentation of osteomalacia is more insidious in the elderly, but proximal myopathy may be severe enough to cause a waddling gait and mimic a primary muscle disorder. The other clinical findings listed are found only in rickets.', 'role': 'assistant'}]