The organ that removes nitrogenous waste from the body is the kidneys. The kidneys are part of the urinary system and play a vital role in maintaining the body's internal balance. They filter waste products, including nitrogenous waste, from the blood and produce urine. The urine containing the waste products is then transported to the bladder for storage before being eliminated from the body through the urethra. Therefore, the correct answer is the kidneys.
