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.

Input: Consider Input: During which process does a caterpillar become a butterfly?  
 (A) fertilization (B) metamorphosis (C) asexual reproduction (D) biological adaptation

Output: B


Input: Consider Input: Evidence of organisms that lived on Earth a long time ago would most likely be found in  
 (A) crystals. (B) lava. (C) sedimentary rock. (D) metamorphic rock.

Output: C


Input: Consider Input: Which of these can make a shadow on the ground during the day?  
 (A) River (B) Air (C) Thunder (D) Cloud


Output: D