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 student adds a handful of snow to a glass of warm water. The water *** will  (A) increases (B) decrease (C) stay the same (D).
Example Output: A.

Example Input: Question: The ***'s *** on its *** *** ___.  (A) the duration of a year (B) climate change (C) seasons (D) day and nigh.
Example Output: E.

Example Input: Question: The systems of the human body work together. Which system works with the skeletal system by pulling on the bones to create movement?  (A) digestive (B) circulatory (C) muscular (D) nervou.
Example Output:
C.