Definition: 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").
Input: Fact1: waxy leaves are used for storing water by some plants, Fact2: Many cacti also have a waxy coating that helps the plant conserve moisture in desert climates., Question: What do some cacti use waxy leaves for? (A) hydration (B) Chemical energy (C) storing water (D) it needs them (E) support (F) survival (G) to stay warm (H) cellulose
Output:
C