This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Peripheral Nerve & Skeletal Muscles, Subject name: Pathology
[{'content': 'A 5-year-old male presented to AIIMS pediatrics OPD with a chief complaint of difficulty in climbing stairs and getting up from sitting position. There was history of maternal uncle having the same illness. On examination; there was pseudohypertrophy of calf muscle. Biopsy of the muscle was performed as shown below. What is your diagnosis? \nSelect and explain. \nA. Duchenne muscular dystrophy, B. Myotonic dystrophy, C. Facioscapulohumeral muscular dystrophy, D. Nemaline myopathy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Duchenne muscular dystrophy*This is myopathy with X-linked inheritance suggested by same history in maternal uncle. On muscle biopsy prominent variation in size of muscle fibers can be seen.', 'role': 'assistant'}]