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 these human activities in a forest has a *** effect on the ecosystem?  (A) Clearing the land to build new homes (B) Planting new trees where old ones were cut down (C) Building a new highway through the area (D) Cutting down trees to make farmlan.
Example Output: 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: During which season would a bear hibernate?  (A) summer (B) fall (C) spring (D) winte.
Example Output:
D.