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 protein is defective in Becker muscular dystrophy? \nSelect and explain. \nA. Dystrophin, B. Actinin, C. Myotilin, D. Emerin', 'role': 'user'}, {'content': "Answer: A \nExplanation: In both Duchenne and Becker's gene encoding for Dystrophin is defective.\nIn Duchenne - Dystrophin is completely absent.\nIn Beckers - Dystrophin is decreased.", 'role': 'assistant'}]