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:
Compost piles have many parts, such as leaves, moisture, vegetables, and microorganisms. Which part of a compost pile breaks down materials and adds nutrients to the soil?  
 (A) leaves (B) moisture (C) vegetables (D) microorganisms
answer:
D


question:
Which item is designed to change electrical energy into heat energy?  
 (A) Alarm clock (B) Hand dryer (C) Fan (D) Telephone
answer:
B


question:
In 2001, NASA launched a probe to investigate very low-energy radiation emitted when the universe began. What part of the electromagnetic spectrum does this probe observe and record?  
 (A) infrared (B) microwave (C) ultraviolet (D) visible
answer:

B