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:
What is the function of the nucleus in a cell?  
 (A) provides energy (B) provides nutrients (C) controls activity (D) controls movement
answer:
C


question:
Which of these technologies helps a power company use renewable energy for the production of electricity?  
 (A) hydroelectric power (B) nuclear power plants (C) natural gas generators (D) coal-fired power plants
answer:
A


question:
The amount of which greenhouse gas in the air will increase the most if large forests are cut down to be used for building materials without planting new trees in their place?  
 (A) ozone (B) methane (C) water vapor (D) carbon dioxide
answer:

D