You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Example Input: Eyeglasses have two arms called temples attached to the eye lenses by very small hinges. Which of these functions like the hinges on eyeglasses?
(A) knee (B) fingers (C) neck vertebrae (D) base of the thumb
Example Output: A

Example Input: A ball is rolling on the ground. A force pushes the ball in the same direction that it is moving. What happens to the ball?
(A) It stops moving. (B) It moves slower. (C) It moves faster in the same direction it was moving. (D) It keeps moving in the same speed and direction.
Example Output: C

Example Input: Which of these is a way that sunglasses help protect the eyes?
(A) reflecting light rays away from the eyes (B) refracting more light rays into the eyes (C) reflecting more light rays into the eyes (D) refracting light rays away from the eyes
Example Output:
A