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).

[EX Q]: Question: If you burn a piece of paper, which property of the paper has changed?  (A) chemical (B) magnetic (C) physical (D) electrica?
[EX A]: C.

[EX Q]: Question: An organism's lifespan ends with  (A) Death (B) Reproduction (C) Growth (D) Egg?
[EX A]: A.

[EX Q]: Question: Decomposers serve important roles in an ecosystem. One of the things they do is ___.  (A) reduce nutrients in the soil (B) reduce insect populations (C) recycle nutrients (D) recycle wate?
[EX A]:
C.