Which of the following is a nitrogenous waste product? Check all that apply.

A) erythropoietin
B) urea
C) uric acid
D) bile pigments
E) creatinine

Erythropoietin is a hormone produced by the kidneys that stimulates the production of red blood cells and is not a nitrogenous waste product. Urea, uric acid, and creatinine are all waste products that result from the breakdown of proteins and nucleic acids in the body. Bile pigments are waste products from the breakdown of hemoglobin in old red blood cells and are excreted in the feces rather than in urine.