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: The change in fur color of the Arctic hare from brown in the summer to white in the winter is an example of  (A) mimicry. (B) heredity. (C) diversity. (D) camouflage?
[EX A]: D.

[EX Q]: Question: What precaution must be taken by students when making observations of the Sun?  (A) Use only new equipment. (B) Use a very strong telescope. (C) Project image onto a piece of cardboard. (D) Look at the Sun only in the morning?
[EX A]: C.

[EX Q]: Question: When is a human considered to have reached the 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 A]:
D.