• Option (3) is correct because myasthenia gravis is a chronic auto immune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle. • Gout is caused due to deposition of uric acid crystals in joints leading to its inflammation. • Inflammation of joints is commonly known as arthritis. • Muscular dystrophy is a genetic disorder which results in progressive degeneration of skeletal muscle.