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 these warms most of the air, water, and land on Earth?  
 (A) Coal (B) Electricity (C) Sunlight (D) Wind

SOLUTION: C

PROBLEM: In a northern state, a room used for growing plants is not allowing enough light to enter for healthy plant growth. Adding windows in walls facing which direction would best solve this problem?  
 (A) north (B) south (C) east (D) west

SOLUTION: B

PROBLEM: When European settlers first came to North America, the average thickness of the top layer of soil was approximately 23 cm. Today, the average thickness of the top layer of soil is less than 15 cm. Which of the following factors has most likely had the greatest effect on erosion of the top layer of soil?  
 (A) farming (B) restoring wetlands (C) species reintroduction (D) excessive groundwater use

SOLUTION:
A