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: When a guitar string is plucked, sound is produced by  (A) the size of the guitar. (B) the metal on the guitar. (C) the wood on the guitar. (D) the vibrations of the string?

Ex Output:
D.


Ex Input:
Question: We are able to see the moon in the sky because the  (A) moon is only visible at night. (B) Earth's light is reflected off of the moon. (C) moon gives off light. (D) sun's light is reflected off of the moon?

Ex Output:
D.


Ex Input:
Question: Ellie is growing a vegetable garden. In which season do the plants in Ellie's garden receive the most energy from the Sun for growing?  (A) fall (B) spring (C) summer (D) winte?

Ex Output:

C.