In this subtask, you will answer a simple science question. Please indicate the correct answer. If you're not sure about the answer, choose the last option "I don't know". Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'. The "A"-"D" responses correspond to the answer options mentioned in the input. There is a 5th option "E" which should be used for questions for which you're not sure about the answer (e.g., when the questions do not provide enough information to answer).

Example Input: Question: How are a tree and grass alike?  (A) Both make wood. (B) Both have roots. (C) Both need moonlight. (D) Both have short lives?
Example Output: B.

Example Input: Question: The moon ____ around the Earth.  (A) grows (B) revolves (C) rotates (D) tilt?
Example Output: B.

Example Input: Question: Which of the following activities is harmful for the environment?  (A) recycling waste (B) conserving water (C) producing waste (D) reducing pollutio?
Example Output:
C.