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: When can producers make the most food?  (A) summer, because there is more sunlight (B) summer, because there is more heat (C) spring, because there is more rain (D) spring, because there are more leave.

Ex Output:
A.


Ex Input:
Question: On a hiking *** to Big *** National ***, a *** found a *** ***. The *** would like to *** the *** of the ***. Which *** would be used to *** the *** of the ***?  (A) Incline plane (B) Balance (C) Meter stick (D) Graduated cylinde.

Ex Output:
E.


Ex Input:
Question: Gordon reads that if an object is closer to the center of a planet, then the force of gravity will be stronger. According to this information, where would the force of gravity be the strongest?  (A) in a flying airplane (B) on a tall mountain (C) in a deep valley (D) on an islan.

Ex Output:

C.