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: Oxygen reacts with iron to produce rust and with hydrogen to produce water. Which statement describes both reactions?  
 (A) A different mixture is formed in each case. (B) A different solution is formed in each case. (C) Both a change of state and of elements is involved. (D) New molecules are formed but the same elements exist.

SOLUTION: D

PROBLEM: A student is designing a model of the solar system and writing a report. She is trying to be as accurate as possible. Which statement should she include in her report?  
 (A) The distance between the Sun and Earth is measured in light years. (B) Jupiter and Uranus are considered to be terrestrial planets. (C) The asteroid belt is located between Jupiter and Saturn. (D) The orbit of Mars is similar to the orbit of Saturn.

SOLUTION: D

PROBLEM: The top layers of soil are important because they -  
 (A) prevent earthquakes (B) give plants nutrients (C) protect the bedrock (D) make walking easier

SOLUTION:
B