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: Which of the following is the BEST example of something that causes a *** *** in the earth's surface?  (A) rainbows (B) floods (C) global warming (D) glacier.
Example Output: E.

Example Input: Question: For a plant to stay *** ***, where does it need to be ***?  (A) In a dry area (B) In a dark room (C) On a plant stand (D) Near a sunny plac.
Example Output: E.

Example Input: Question: A student puts two identical plants *** the same type and amount of soil. She gives them the same amount of water. She puts one of these plants near *** *** *** and the other *** *** dark room. This experiment tests how the plants respond to  (A) light (B) air (C) water (D) soil.
Example Output:
A.