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]: In an experiment studying phototropism, students grew bean plants in labeled cardboard milk cartons. Afterward, the plants and soil were properly discarded. Which instruction line BEST conserves the remaining resources?  
 (A) recycle the markers, reuse the milk cartons (B) reuse the markers, discard the milk cartons (C) discard the markers, reuse the milk cartons (D) reuse the markers, recycle the milk cartons
[A]: D


[Q]: 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
[A]: C


[Q]: There are many different processes that take place in plant and animal cells. Cellular respiration is one of those processes. What is the purpose of cellular respiration?  
 (A) To make and store food (B) To add oxygen to the atmosphere (C) To release energy from stored food (D) To remove carbon dioxide from the atmosphere
[A]:
C