I'm almost sure its by the urinary system.
Urinary system
The excretory system removes waste from the body's metabolism and the digestive system removes waste from the body
The urinary system or renal system removes liquid and waste from the blood and transports them to the outside of the body. The kidneys remove waste, from the blood, which travels down the ureters into the bladder from where it passes through the urethra as urine.
The respiratory system removes gaseous waste such as carbon dioxide from the body. This waste is eliminated when we exhale.
digestive
Cardiovascular system (consisting of the heart, blood and blood vessels).
The excretory (urinary) system removes liquid wastes from the body
The body system responsible for removing liquid and waste from the blood and transporting them to the outside of the body is the excretory system. The main organs involved in this process are the kidneys, which filter the blood to remove waste and excess fluid, producing urine. The urine then travels through the ureters to the bladder, where it is stored until it is expelled from the body through the urethra. This process helps maintain the body's internal balance and eliminate harmful substances.
The circulatory system is responsible for transporting blood throughout the body. It includes the heart, blood vessels, and blood itself. This system delivers oxygen, nutrients, and hormones to cells, and removes waste products.
The excretory system.
Renal system ( the kidneys )
The Excretory System removes wastes. This system includes the skin, the lungs, the liver, the kidneys, and the large intestine. The skin removes sweat. The lungs remove carbon dioxide and water vapor. The liver removes the breakdown of red blood cells in the form of bile. The kidneys remove toxins from the blood. The large intestine removes feces.