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: Some parasites live on the surface of their host., Fact2: Fleas and ticks are parasites., Question: what sometimes lives on the surface of their host? (A) lungs (B) an organism's body (C) human (D) barnacles (E) fleas and ticks (F) density (G) sensory neurons (H) bacteria
Output:
E