Answer:
The kidneys, although the liver is involved in hemoglobin breakdown. The liver is not an excretory organ, so it is the kidneys which break down red blood cells and produces urea, but that urea is not just from blood cells. In fact, hardly any of it is. Urea is largely composed of nitrogenous wastes given off by cells, and ammonia is NH3. Hope This Helps.
Step-by-step explanation: