Auto immune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle is

The correct option is D Myasthenia gravis

• Muscular dystrophy is a disease characterized by progressive degeneration of muscle fibers without the involvement nervous system. It has a hereditary origin.
  
• Tetany is overly stimulated nerve which causes involuntary muscle cramps and contractions. it caused by low level of calcium.
  
• Gout is caused by two conditions one due to excessive formation of uric acid second by the inability to excrete it. Uric acid gets deposited in joint as monosodium salts.
  
• Myasthenia gravis is an autoimmune disease of neuromuscular junction caused by antibodies to cholinergic receptors. it is characterized by grave weakness of the muscles due to the inability of neuromuscular junctions to transmit impulses from nerve to the muscle.
  

Thus the correct answer is option D.