A staff nurse is teaching a client who has Addison's disease about the disease process. The client asks the nurse what causes Addison's disease. Which of the following responses should the nurse make?

"It is caused by the lack of production of aldosterone by the adrenal gland."

"It is caused by the overproduction of growth hormone by the pituitary gland."

"It is caused by the lack of production of insulin by the pancreas."

"It is caused by the overproduction of parathormone by the parathyroid gland."