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.

Example Input: A scientist studies the remains of two extinct animals to learn more about how they lived. She determines that one animal was a carnivore and the other was an herbivore. Which of the following did the scientist most likely compare to make this conclusion?  
 (A) the number of bones in the animals (B) the size of the animals (C) the body covering of the animals (D) the skull of the animals
Example Output: D

Example Input: Which of these is a nonliving part of a forest?  
 (A) Tree (B) Soil (C) Worm (D) Mushroom
Example Output: B

Example Input: When a scientist performs an experiment, there are many changes that can occur. Which observation should she list as a chemical change?  
 (A) The substance was heated. (B) The shape of the substance changed. (C) The volume of the substance changed. (D) The substance changed into a new substance.
Example Output:
D