Where is urobilinogen primarily produced in the body?

Urobilinogen is primarily produced in the liver and the intestines. After the liver metabolizes bilirubin, it is excreted into the bile and then enters the intestine. In the intestines, bacteria convert bilirubin into urobilinogen. Some of this urobilinogen can be reabsorbed back into the bloodstream and is eventually excreted in urine or converted to urobilin, which gives feces its characteristic brown color.

The liver plays a pivotal role in the production of bile, which is essential for the metabolism of bilirubin. The liver's function in bilirubin metabolism is crucial for the overall process that leads to urobilinogen formation. Therefore, identifying the liver as a key producer of urobilinogen, along with the role of the intestines in its conversion from bilirubin, supports the correctness of the answer.