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: A *** *** *** *** it *** *** that are *** on ***. This *** can be *** a(an)  (A) adaptation. (B) difficulty. (C) camouflage. (D) migration.

Ex Output:
E.


Ex Input:
Question: We are able to see the moon in the sky because the  (A) moon is only visible at night. (B) Earth's light is reflected off of the moon. (C) moon gives off light. (D) sun's light is reflected off of the moon.

Ex Output:
D.


Ex Input:
Question: When *** *** human *** *** *** reached *** adult stage?  (A) When cells no longer divide (B) When the human has begun to talk (C) When the human has begun to walk (D) When most growth has stoppe.

Ex Output:

D.