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: Medicine
The electromyogram (EMG) is least useful for the diagnosis of - 
Select and explain. 
A. Cerebral palsy, B. Spinal muscular atrophy, C. Charcot - Marie - Tooth disease, D. Myasthenia gravis
A: Cerebral palsy
Answer: A: Cerebral palsy 
Explanation: None