Unknown A 7years old boy has progressive difficulty in climbing the stairs and walks with waddling gait also has calf muscle hypertrophy diagnosis is A DMD B Myositis C Dermatomyositis D Becker's muscular dystrophy 💡 Explanation A 7years old boy has progressive difficulty in climbing the stairs and walks with waddling gait also has calf muscle hypertrophy diagnosis is ✓ Correct Answer: D. Becker's muscular dystrophy