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.

Ex 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

Ex Output:
A


Ex Input:
Which pair of organisms benefits each other the most?  
 (A) birds building a nest in a bush (B) worms eating the roots of a plant (C) squirrels burying seeds from a tree (D) deer scraping their antlers on a tree

Ex Output:
C


Ex Input:
Which of these would be the best representation of the particles in a solid material?  
 (A) The football players playing on the field. (B) The planes flying over the football stadium. (C) The spectators sitting in their seats at the football stadium. (D) The spectators arriving at the football stadium and moving to their seats.

Ex Output:

C