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'.

Ex 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.

Ex Output:
E.


Ex Input:
Question: Kyle designed an *** to see if the number of *** increased in the soil next to his house. How should he begin his investigation?  (A) Count the number of earthworms that are already there (B) Make sure that there are no other organisms located in the soil (C) Clean out the plants in the garden (D) Make sure that the soil is mois.

Ex Output:
E.


Ex Input:
Question: Scientists observed several different organisms in the same *** environment. Which of the following organisms in this *** environment *** on *** *** and *** material for ***?  (A) cockroach (B) tree (C) snake (D) robi.

Ex Output:

E.