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 muscle fatigability is a feature of: 
Select and explain. 
A. Facial palsy., B. Myasthenia gravis., C. MPDS., D. All of the above.
B: Myasthenia gravis.
Answer: B: Myasthenia gravis. 
Explanation: None