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: A plant in a food chain is called the  (A) producer. (B) consumer. (C) decomposer. (D) energizer?
Example Output: A.

Example Input: Question: An influence that can change the motion of an object, such as its speed or direction, is called ___.  (A) solubility (B) buoyancy (C) force (D) potential energ?
Example Output: C.

Example Input: Question: Owen tested a physical property of a mineral. He rubbed a mineral sample on a piece of white tile. The mineral left a red mark on the tile. Which of the following physical properties of the mineral was Owen most likely testing?  (A) cleavage (B) hardness (C) luster (D) strea?
Example Output:
B.