instruction:
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.
question:
Planets in the solar system are in constant motion. What factor has the greatest effect on the orbits of the planets?  
 (A) the size of the planets (B) gravitational pull of the Sun (C) the composition of the planets (D) electromagnetic radiation from the Sun
answer:
B


question:
Which physical structure would best help a bear to survive a winter in New York State?  
 (A) big ears (B) black nose (C) thick fur (D) brown eyes
answer:
C


question:
At what temperature does pure water boil?  
 (A) 0°C (B) 32°C (C) 100°C (D) 212°C
answer:

C