Given the task definition and input, reply with output. In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: Urine leaves the body through a sphincter in the process of urination., Fact2: From the bladder, urine leaves the body., Question: Urine has to pass through what as the bladder empties? (A) epidermal (B) body water (C) a sphincter (D) all liquids (E) mouth of rivers (F) alveoli (G) salt and water. (H) aqueous solution
C