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: Which mixture contains ingredients that can be easily separated?  (A) bread (B) fruit salad (C) ocean water (D) soda wate?

Ex Output:
B.


Ex Input:
Question: What trait might a tiger inherit from its parents?  (A) Choice of mate (B) Hunting skills (C) Personality traits (D) Fur colo?

Ex Output:
D.


Ex Input:
Question: What tool is used to determine the mass of an object?  (A) Balance (B) Meter stick (C) Thermometer (D) Graduated cylinde?

Ex Output:

A.