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.

Q: The engineering team that is designing a scientific research station on the Arctic permafrost has to provide the station with energy for cooking, heating, and lighting. Considering the fragile environment and other conditions there, the best choice is probably to  
 (A) build a wind turbine. (B) have fuel trucked in. (C) have a pipeline built. (D) build a solar collector.

A: A
****
Q: When animals use energy, they produce  
 (A) nitrogen (B) iron sulfide (C) oxygen (D) carbon dioxide

A: D
****
Q: A broken bone heals through the process of  
 (A) adaptation (B) mutation (C) cell division (D) chemical digestion

A:
C
****