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: *** event *** cause *** large rock *** become soil *** time?  (A) decaying (B) an earthquake (C) a landslide (D) weatherin.
[EX A]: D.

[EX Q]: Question: If *** A competes with *** B, and *** A is ***, what will most likely happen to *** B?  (A) It will continue to live with species (A) (B) It will join with another species to compete with species (A) (C) It will move to another area away from species (A) (D) It will keep competing until species A is extinct.
[EX A]: E.

[EX Q]: Question: What causes nighttime and daytime on Earth?  (A) the Sun rotating on its axis (B) Earth rotating on its axis (C) Earth revolving around the Sun (D) the Moon revolving around Eart.
[EX A]:
B.