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:
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:
Which action involving a pulley system requires the least amount of force?  
 (A) using several pulleys together instead of a single pulley (B) using a fixed pulley instead of a moveable pulley (C) pulling a long rope instead of a short rope (D) pulling a rope up instead of down

Ex Output:
A


Ex Input:
A book placed on a table is observed to remain stationary. Which statement about the observation would be considered a fact rather than an opinion?  
 (A) The book is not very heavy. (B) The table pushes up on the book. (C) The book probably has a sticky cover. (D) The table is composed of a stronger material than the book.

Ex Output:

B