The right option is; a. liver.
The liver is a large, important organ that is situated on the right side of the stomach. The liver is enclosed by the rib cage and it has two large sections (the right and the left lobes). The main function of the liver is to filter the blood coming from the digestive tract, before transporting it to the other parts of the body. The liver also detoxifies chemicals, regulates glycogen storage, metabolizes drugs and synthesizes proteins essential for blood clotting and other functions in the body.