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: What is made when sugar is dissolved in water?  (A) a colloid (B) a solution (C) a suspension (D) an evaporatio.
[EX A]: B.

[EX Q]: Question: *** *** *** *** source *** heat energy *** Earth?  (A) fire (B) volcanoes (C) the sun (D) electricit.
[EX A]: C.

[EX Q]: Question: Rachel purchased a kit for making a skateboard ramp. Which of the following is most *** to have for *** the ramp ***?  (A) a picture showing the colors of different ramp parts (B) a diagram showing some ways to use the ramp (C) a list of prices for other available kits (D) a set of instructions for the kit material.
[EX A]:
D.