You are presented with the question "Urine has to pass through what as the bladder empties?" and the following answer choices: 
- epidermal
 - body water
 - a sphincter
 - all liquids
 - mouth of rivers
 - alveoli
 - salt and water.
 - aqueous solution

Now knowing that urine leaves the body through a sphincter in the process of urination and from the bladder, urine leaves the body, choose the best answer.


 

   a sphincter      