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

Fact 2: Urine tests detect drugs used up to 36 hours before a given urine collection.

Given the two facts above, answer the question "Which bodily system excretes a substance commonly used in drug testing?" with the following options: 
- Evaporation
 - urinary system
 - animals
 - aqueous solution
 - cardiovascular system
 - opiate system
 - Integumentary system
 - sweating


 

  urinary system       