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
Easy fatigability of muscles seen in: 
Select and explain. 
A. Epilepsy, B. MPDS, C. Myasthenia gravis, D. Cerebral palsy
C: Myasthenia gravis
Answer: C: Myasthenia gravis 
Explanation: None