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: Which change will occur in the wire of an electrical circuit that is working properly?  (A) The wire will become warmer. (B) The wire will lose some of its mass. (C) The wire will form an electric field. (D) The wire will develop a new crystal structure?
[EX A]: A.

[EX Q]: Question: Which device is used to determine the volume of a liquid?  (A) anemometer (B) graduated cylinder (C) test tube (D) thermomete?
[EX A]: B.

[EX Q]: Question: Which of the following represents a chemical reaction?  (A) a sugar cube dissolving in water. (B) ice cubes forming in a freezer. (C) ice cream melting in a bowl. (D) a cake baking in an oven?
[EX A]:
D.