You are given a science question (easy-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:
Which statement correctly describes a relationship between two human body systems?
(A) The digestive system absorbs nutrients which are transported by the nervous system. (B) The digestive system absorbs nutrients which are transported by the circulatory system. (C) The circulatory system exchanges gases which are transported by the nervous system. (D) The circulatory system exchanges gases which are transported by the digestive system.

Ex Output:
B

Ex Input:
A student is designing a model of the solar system and writing a report. She is trying to be as accurate as possible. Which statement should she include in her report?
(A) The distance between the Sun and Earth is measured in light years. (B) Jupiter and Uranus are considered to be terrestrial planets. (C) The asteroid belt is located between Jupiter and Saturn. (D) The orbit of Mars is similar to the orbit of Saturn.

Ex Output:
D

Ex Input:
Which physical characteristic do some organisms have that helps them survive in the Arctic?
(A) growing tall to hide in trees (B) changing fur color to hide from predators (C) developing large paws to protect themselves from the wind (D) producing shallow root systems to protect themselves from the cold air

Ex Output:
B