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: Pathology
[{'content': 'Which of the following disorder is classified under defects in metabolic pathways? \nSelect and explain. \nA. Cherubism, B. Robinow syndrome, C. Severe infantile osteopetrosis, D. Pycnodysostosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]