In this task, you need to answer basic science questions. For each question, several terms are intentionally masked with ***. This masking can cover very few or many of the question words. Clearly, if masked terms are important, the modified question will be impossible to answer. Please indicate the correct answer with one of the following responses: "A", "B", "C", "D" or "E". While "A"-"D" correspond to the answer options provided in the input, "E" represents "I don't know" for questions that do not provide enough information. Respond via "E" if the question is not answerable. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'.

[Q]: Question: Which of the following would result in a decrease in the polar bear population in the arctic?  (A) An increase in the amount of grass (B) An increase in the fish population (C) A decrease in the fish population (D) A decrease in the human populatio.
[A]: C.


[Q]: Question: A company plants trees on a bare hillside. Which of these is the BEST reason for planting the trees?  (A) The trees provide oxygen for the soil. (B) The trees prevent soil from washing away. (C) The trees make shade for animals living there. (D) The trees cause animals to move to other places.
[A]: B.


[Q]: Question: What are the bundles of chemicals in our body called that control what we look like?  (A) cells (B) genes (C) DNA (D) filament.
[A]:
B.