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: *** *** *** following units *** *** likely *** used *** describe *** mass *** *** horse?  (A) meters (B) centigrams (C) kilograms (D) millimeter.
[EX A]: C.

[EX Q]: Question: *** *** *** *** *** *** ****** *** *** *** *** *** *** ***d?  (A) In a dry area (B) In a dark room (C) On a plant stand (D) Near a sunny plac.
[EX A]: E.

[EX Q]: Question: In studying *** of *** ***, a *** found an area where *** *** was *** on *** of *** rock. Which best *** how this ***?  (A) Earthquake activity folded the rock layers. (B) Volcanic eruptions destroyed a rock layer. (C) Erosion removed several layers of rock. (D) Weathering changed the layering of the rocks.
[EX A]:
E.