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: microorganisms can cause infections, Fact2: Chlorination uses liquid chlorine bleach to kill microorganisms., Question: Which chemical added to water prevents illnesses? (A) Glucose (B) evaporation (C) Chlorine. (D) sugar (E) Allergies (F) sweating (G) energy (H) hydration
C