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: Which of the following best describes a mineral?  
 (A) a solid natural material with a crystal structure (B) a material that was once living but has decayed (C) a liquid chemical used to make soil more fertile (D) a nutrient produced by plants that other organisms need

SOLUTION: A

PROBLEM: Most of the United States is a part of which tectonic plate?  
 (A) Pacific Plate (B) Eurasian Plate (C) North American Plate (D) South American Plate

SOLUTION: C

PROBLEM: The surface of Earth is composed of large tectonic plates that are constantly shifting as they float on top of molten rock. Which process must occur in the mantle to make the plates move?  
 (A) normal faulting (B) seafloor spreading (C) igneous intrusions (D) convection currents

SOLUTION:
D