This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolic Bone Disease, Subject name: Orthopaedics
[{'content': 'Marble bone disease is \nSelect and explain. \nA. Osteogenesis imperfect, B. Osteopetrosis, C. Osteomyelitis, D. Osteoporosis', 'role': 'user'}, {'content': "Answer: B \nExplanation: (Osteopetrosis): (307- Malushwari 4th edition)OSTEOPETROSIS (Marble bones, Alber's - Schonberg disease)* Characterised by dense but brittle bones* Autosomal dominant disorderCP-* Pathological fractures* Cranial nerve compression]---Due to bone encroachment on foramena* Jaw osteomyelitis (After tooth extraction)* Anemia* X-ray shows - Increased density of the all the all the bones* Cortices are widened leaving narrow medullary canal Sclerotic vertebral end plates producing a striped appearance (rugger Jersey spine)* Skull is thickened and the base densely sclerotic", 'role': 'assistant'}]