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 Input:
Question: A student puts two identical plants in the same type and amount of soil. She gives them the same amount of water. She puts one of these plants near a sunny window and the other in a dark room. This experiment tests how the plants respond to  (A) light (B) air (C) water (D) soil?

Ex Output:
A.


Ex Input:
Question: Air and water are necessary for ____ to survive.  (A) plants (B) animals (C) both plants and animals (D) nonliving thing?

Ex Output:
C.


Ex Input:
Question: Water freezing is an example of a  (A) liquid changing to a solid (B) solid changing to a liquid (C) gas changing to a solid (D) gas changing to a liqui?

Ex Output:

A.