You are given a science question (hard-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: Morning glories are plants that have a large amount of variation in the genes for flower color. When a white flower appears in a population independent of the trait for white flower color, what is the most likely source?  
 (A) genetic mutation (B) selective breeding (C) genome duplicating (D) sexual recombination

Output: A


Input: Consider Input: A young ocean animal has two parents. Each of the parents has eight arms. How many arms does the young animal most likely have?  
 (A) 2 (B) 4 (C) 8 (D) 16

Output: C


Input: Consider Input: Certain lakes in the northeastern part of the United States have had decreases in pH levels, causing the deaths of many fish. What is the most likely reason for this change in pH levels?  
 (A) nuclear power plants (B) hydroelectric power plants (C) coal-burning factories (D) noncommercial farms


Output: C


