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': 'Mutation in GNAS 1 gene is associated with \nSelect and explain. \nA. Fibrous dysplasia, B. Ossifying fibroma, C. Focal cementoosseous dysplasia, D. Periapical cementoosseous dysplasia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]