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: *** *** *** *** *** *** *** *** *** *** ****** *** ****** ****** *** ***?  (A) the Sun (B) the Moon (C) Earth's gravity (D) Earth's rotatio.
Example Output: E.

Example Input: Question: *** serve important *** in an ***. One of the things they do is ___.  (A) reduce nutrients in the soil (B) reduce insect populations (C) recycle nutrients (D) recycle wate.
Example Output: E.

Example Input: Question: Which of the following items in a *** *** *** with the *** of an ***?  (A) dump truck (B) crane to pick up, haul, and drop cars (C) fence that surrounds the wrecking yard (D) dumpster for leftover part.
Example Output:
E.