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 Q]: Question: Which mixture contains ingredients that can be easily separated?  (A) bread (B) fruit salad (C) ocean water (D) soda wate.
[EX A]: B.

[EX Q]: Question: When a guitar string is plucked, sound is produced by  (A) the size of the guitar. (B) the metal on the guitar. (C) the wood on the guitar. (D) the vibrations of the string.
[EX A]: D.

[EX Q]: Question: Kyle designed an *** to see if the number of *** *** in the *** next to his house. How should he *** 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 A]:
E.