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'.

Example Input: Question: *** *** *** tree *** grass alike?  (A) Both make wood. (B) Both have roots. (C) Both need moonlight. (D) Both have short lives.
Example Output: B.

Example Input: Question: *** *** *** *** *** result *** *** decrease *** *** polar bear population *** *** ***?  (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.
Example Output: C.

Example Input: Question: What should be done when the results of an experiment do *** support the hypothesis?  (A) repeat the experiment and check for errors (B) change the observations to match the hypothesis (C) redo the experiment until the expected results are obtained (D) record and analyze the data after changing the hypothesi.
Example Output:
A.