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: Radiology
[{'content': 'Which of the following condition gives the characteristic radiological finding "bone within a bone" appearance? \nSelect and explain. \nA. Osteogenesis imperfecta, B. Osteopetrosis, C. Scurvy, D. Rickets', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Radiologic examination of osteopetrosis shows increased bone density and transverse bands in the shafts, clubbing of ends, and veical striations of long bones. Thickening about the cranial foramina is present, and heterotopic calcification of soft tissues is possible. Other characteristic findings include a miniature bone inset within each veebral body (bone-within-a bone appearance) and increased density at the end plates (sandwich veebrae). Ref: Clinical Imaging: An Atlas of Differential Diagnosis By Ronald L. Eisenberg, 2012, Page 1088.', 'role': 'assistant'}]