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 Q]: 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 A]: C

[EX Q]: Which substance do all living things require to survive?  
 (A) blood (B) water (C) carbon dioxide (D) organic soil
[EX A]: B

[EX Q]: Which material is attracted to a magnet?  
 (A) iron (B) wood (C) plastic (D) ice
[EX A]:
A