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: The continuous changes of a seed to an adult plant that produces seeds is known as a  (A) lunar cycle. (B) weekly cycle. (C) daily cycle. (D) life cycle?

Ex Output:
D.


Ex Input:
Question: A giraffe's long neck helps it eat leaves that are high on trees. This trait can be considered a(an)  (A) adaptation. (B) difficulty. (C) camouflage. (D) migration?

Ex Output:
A.


Ex Input:
Question: What is the main source of heat energy on Earth?  (A) fire (B) volcanoes (C) the sun (D) electricit?

Ex Output:

C.