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
Perifasicular atrophy of muscle fibres is seen in? 
Select and explain. 
A. Dermatomyositis, B. Steroid myopathy, C. Inclusion body myositis, D. Viral myositis
A: Dermatomyositis
Answer: A: Dermatomyositis 
Explanation: A distinctive feature of dermatomyositis is atrophy and degeneration of myofibres at the periphery of fasicles (perifasicular) which occurs even in the absence of inflammation.