TASK DEFINITION: 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.
PROBLEM: Greenhouse gases in the atmosphere absorb infrared radiation from Earth's surface and re-radiates some of it back to Earth. Which of these gases have the most significant impact on the temperature of Earth's atmosphere?  
 (A) nitrogen and argon (B) oxygen and sulfur dioxide (C) carbon dioxide and water vapor (D) hydrochloric acid and hydrogen

SOLUTION: C

PROBLEM: Which of these will most likely harm a habitat?  
 (A) planting trees (B) water pollution (C) rainfall (D) sunlight

SOLUTION: B

PROBLEM: Oscar and Andre used a microscope to observe a sample of pond water and drew an example of each type of organism they saw. Then they compared their drawings. They discovered that their drawings of a euglena and a paramecium were alike, but their amoeba drawings had very different shapes. What are two things that Oscar's amoeba could have been doing that made his drawing look different from Andre's?  
 (A) eating and moving (B) moving and digesting (C) digesting and excreting (D) excreting and eating

SOLUTION:
A