The answer is letter D.
When the body is experiencing stress it usually responds by producing additional enzymes in the liver and kidneys causing an increase in blood flow in these organs. Not only is stress visible on the outside but it clearly affects how the internal organs function within the body. Stress induces chemical reactions in the brain that trigger the response of the immune system of the body. The kidneys and the liver are part of the filtration and excretion of chemical processes that occur within the body that is why they are affected by stress hormones directly.