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 most sensitive test for the diagnosis of myasthenia gravis is - 
Select and explain. 
A. Elevated serum ACH-receptor binding antibodies, B. Repetitive nerve stimulation test, C. Positive edrophonium test, D. Measurement of jitter by single fibre electromyography
C: Positive edrophonium test
Answer: C: Positive edrophonium test 
Explanation: None