The correct option is A 1 - a, 2 - c, 3 - b, 4 - d
Autoimmunity refers to the body’s development of intolerance to the antigens on its own cells i.e., there is an immune response to one’s own tissue antigens. Rheumatoid arthritis is an autoimmune disaese in which the person's immune system attacks the joints. This results in inflammation and thickening of the joint. In type I diabetes, immune system destroys insuling producing pancreatic cells resulting in little or no insulin production by the body. In multiple sclerosis, the immune system attacks the protective sheath (myelin) that covers nerve fibres and causes communication problems between brain and the spinal cord. Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body. Addison's disease arises from problems with the adrenal gland such that not enough of the steroid hormone cortisol and possibly aldosterone are produced, most often due to damage by the body's own immune system.