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: seasons cause change to the environment, Fact2: An ecosystem is an environment and all the members of that environment., Question: What is something that changes an ecosystem? (A) seasons (B) herbicide (C) animals (D) Pesticides (E) flooding (F) wind (G) influenza (H) climate
A