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: bacteria in soil convert atmospheric nitrogen into a form usable by plants, Fact2: Nitrogen deficiency increases the stress on the plants., Question: What does bacteria in the soil help to prevent? (A) contamination (B) colder weather (C) Pollution (D) anemia (E) plant stress (F) Greenhouse gasses (G) toxins (H) disease
Output:
E