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 characteristic of sound makes it possible for bats to fly in the dark without hitting any objects?  
 (A) refraction (B) reflection (C) conduction (D) amplification

SOLUTION: B

PROBLEM: Russell wants to observe changes in nature over the next few months. What can a thermometer help Russell investigate?  
 (A) rainfall amounts each week (B) tiny organisms in pond water (C) the high temperatures each day (D) the amount of growth in a plant

SOLUTION: C

PROBLEM: Which energy source could involve a dam?  
 (A) biomass (B) solar power (C) geothermal energy (D) hydroelectric power

SOLUTION:
D

