You are presented with the question "What is a waste product of the body that is excreted by the urinary system?" and the following answer choices: 
- potash
 - food
 - CO 2
 - sugar
 - urea
 - liquid
 - H 2 O
 - sulfur

Now knowing that urine is the liquid waste product of the body that is excreted by the urinary system and mammals excrete urea in the watery form of urine , choose the best answer.


 

     urea    