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: Which event can cause a large rock to become soil over time?  (A) decaying (B) an earthquake (C) a landslide (D) weatherin?
Example Output: D.

Example Input: Question: The Moon orbits the Earth ___.  (A) every 27.3 days (B) every 365.25 days (C) four times a year (D) every da?
Example Output: A.

Example Input: Question: The pollen of one flower and the egg of another are necessary to form seeds. Which one of the following methods transfers pollen to the egg?  (A) Sunlight (B) A butterfly (C) A leaf (D) The stigm?
Example Output:
B.