This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
Absence of dystrophin 
Select and explain. 
A. DMD, B. Myotonic Dystrophy, C. Becker Dystrophy, D. Myasthenia Gravis
A: DMD
Answer: A: DMD 
Explanation: ref : harrisons 21st ed