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.

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
C

Which of the following is most likely to disrupt the natural balance in an ecosystem?  
 (A) introduction of a non-native species (B) reduced daylight hours during winter (C) preventing the cutting of trees in forests (D) riverbank erosion resulting from springtime flooding
A

Turning off the light when leaving a room is an example of  
 (A) conserving energy. (B) wasting energy. (C) using potential energy. (D) using chemical energy.

A