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.

Ex Input:
Which is the best tool for measuring the temperature of lake water?  
 (A) Meter stick (B) Balance (C) Graduated cylinder (D) Thermometer

Ex Output:
D


Ex Input:
What kind of energy conversion occurs after a candle is lit?  
 (A) friction to electrical energy (B) light energy to heat energy (C) mass to kinetic energy (D) chemical energy to light energy

Ex Output:
D


Ex Input:
Solar energy is referred to as the energy of the future because  
 (A) the atmosphere receives many kinds of rays from the Sun. (B) sunlight offers an unlimited amount of energy for the world. (C) the thinning of the ozone layer is damaging the atmosphere. (D) sunlight will not always be available and should be used now.

Ex Output:

B