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.

Example Input: Scientists use ice cores to identify and explain previous climatic trends. By correlating climatic conditions recorded in the ice, with solid, nonsnow particles also found in the ice, scientists can help to predict the climatic impact of which phenomena?  
 (A) atmospheric carbon dioxide concentration changes (B) radioactive decay rate changes in the outer core (C) volcanic eruptions (D) magnetic pole reversals
Example Output: C

Example Input: Research in which of these areas has the greatest impact on the environment?  
 (A) irradiating food (B) organic fertilizers (C) bacteria to clean up oil spills (D) developing larger, sweeter strawberries
Example Output: C

Example Input: A ball is dropped from the top of a tall building. As the ball falls, the upward force of air resistance becomes equal to the downward pull of gravity. When these two forces become equal in magnitude, the ball will      
 (A) flatten due to the forces. (B) fall at a constant speed. (C) continue to speed up. (D) slow to a stop.
Example Output:
B