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'.

[Q]: Question: John was using his *** *** when it suddenly *** ***. What is the first thing John should do to try *** the ***?  (A) recharge the battery (B) take the player apart (C) replace the player with a new one (D) change to a different son.
[A]: E.


[Q]: Question: Which of the following is *** true in *** particular environment?  (A) Some kinds of plants and animals survive well. (B) Some kinds of plants and animals do not survive well. (C) Some kinds of plants and animals cannot survive. (D) Some plants and animals will always survive.
[A]: E.


[Q]: Question: A pencil falls off of a desk. What *** the pencil toward the ***?  (A) mass (B) friction (C) gravity (D) spee.
[A]:
C.