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: *** *** battery-powered flashlight *** turned ****** electrical energy *** transformed ***  (A) light energy. (B) heat energy. (C) chemical energy. (D) energy of motion.
Example Output: A.

Example Input: Question: A *** *** an *** by *** *** *** *** *** of *** for a ***. At the *** of the ***, she *** the *** mice. *** the *** is an *** of  (A) a measurement (B) a hypothesis (C) an explanation (D) background researc.
Example Output: E.

Example Input: Question: A manufacturer wants to produce a container for food storage that does not break easily and is airtight, inexpensive, and microwave-safe. Which of the following is the best material to use to make the container?  (A) glass (B) metal (C) paper (D) plasti.
Example Output:
D.