A 35 year old man with complaints of ptosis, with dificulty in chewing and occasionally swallowing. There is no history of diplopia and on examination there is a symmetrical ptosis, lateral arm abduction time of 60 seconds. Repetitive nerve stimulation test shows decremental response. EMG shows myopathic response. Anti –Ach receptor antibodies are negative. Probable diagnosis is:

• A. Ocular M.Gravis
• B. Generalised M.Gravis
• C. Since Anti-ach receptor antibodies are negative consider other diagnosis
• D. Chronic Progressive external opthalmoplegia