$\bullet$ Option (d) is correct because myasthenia gravis is a chronic auto immune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle.

$\bullet$ Gout is caused due to deposition of uric acid crystals in joints leading to its inflammation.

$\bullet$ Arthritis is the swelling and tenderness of one or more number of joints. It is caused by injury, abnormal metabolism, and genetic makeup.

$\bullet$ Muscular dystrophy is a disease characterised by progressive degeneration of muscle fibres without the involvement of nervous system.