Detailed Instructions: 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").
Problem:Fact1: planting trees has a positive impact on an ecosystem, Fact2: Human beings live within the world's ecosystems., Question: What does planting trees have a positive impact on? (A) animals (B) sun (C) humans (D) watershed (E) stars (F) habitat (G) earth (H) moon
Solution:
C