This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Avascular Necrosis & Osteochondroses, Subject name: Orthopaedics
[{'content': "Kohler's disease involves: \nSelect and explain. \nA. Femoral head, B. Navicular bone, C. Tibial tubercle, D. Lunate bone", 'role': 'user'}, {'content': "Answer: B \nExplanation: (Navicular bone) (269-M)Common osteochondritisNameSite affected* Perthes' disease- Femoral disease* Fanner's disease- Capitulum* Keinbock's disease- Lunate bone* Osgood shlatter's disease- Tibial tubercle* Sever's disease- Calcaneal tuberosity* Kohler's disease- Novicular bone* Fricberg's disease- Metatarsal head* Scheurmann's disease- Ring epiphysis of vertebrae* Calve's disease- Central bony nucleus of vertebral body", 'role': 'assistant'}]