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 of the following forms of energy is released or absorbed in most chemical reactions?      
 (A) light energy (B) electrical energy (C) sound energy (D) heat energy

Ex Output:
D


Ex Input:
What is an environmental threat posed by oil and gas acquisition and transport that is not posed by the acquisition and transport of the energy resources uranium, and wood?  
 (A) habitat change (B) vehicle pollution (C) pipeline leaks (D) soil compaction and loss

Ex Output:
C


Ex Input:
Which is the best example of a parasitic relationship?  
 (A) a woodpecker nesting in a cavity of a dead tree (B) a tapeworm absorbing food in the digestive tract of a wolf (C) a polar bear hunting a seal for food (D) a hummingbird transferring pollen between flowers

Ex Output:

B