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
Thymoma is associated with: 
Select and explain. 
A. Myasthenia gravis, B. Hypergammaglobulinemia, C. SLE, D. Multiple sclerosis
A: Myasthenia gravis
Answer: A: Myasthenia gravis 
Explanation: Approximately 75% of the patients with myasthenia gravis may have thymic abnormalities. About 30% of the patients with myasthenia gravis have thymoma. So Myasthenia gravis is the single best answer of choice. Ref: Harrison's Principles of Internal Medicine, 16th Edition, Page 2521