This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculo Skeletal Disorders, Subject name: Pediatrics
[{'content': 'Osteogenesis imperfecta with normal dentition and sclera: \nSelect and explain. \nA. Type 1A, B. Type 2, C. Type 3, D. Type 4B', 'role': 'user'}, {'content': "Answer: A \nExplanation: a. Type 1A(Ref: Nelson's 20/e p 3381)Osteogenesis imperfecta (OI) is the most common genetic cause of osteoporosis; OI Type I is a mild disease.Both types I & IV are divided into A and B subtypes, depending on the absence (A) or presence (B) of dentinogenesis imperfecta.", 'role': 'assistant'}]