Fact 1: Urine is the liquid waste product of the body that is excreted by the urinary system.

Fact 2: Mammals excrete urea in the watery form of urine .

Given the two facts above, answer the question "What is a waste product of the body that is excreted by the urinary system?" with the following options: 
- potash
 - food
 - CO 2
 - sugar
 - urea
 - liquid
 - H 2 O
 - sulfur


 

     urea    