instruction:
You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.
question:
Which of the following best describes a role of mushrooms in ecosystems?  
 (A) capturing energy from sunlight (B) consuming living plant material (C) taking energy from animal hosts (D) breaking down dead plant material
answer:
D


question:
Use of nuclear fuel would most likely reduce human contributions to which environmental problem?  
 (A) ozone thinning (B) landfill creation (C) shoreline erosion (D) greenhouse heating
answer:
D


question:
When oxygen combines with hydrogen, which substance is formed?  
 (A) water (B) vinegar (C) hydrochloric acid (D) hydrogen dioxide
answer:

A