Question

Carbon dioxide and water vapor help to prevent _______ from escaping from Earth.
a. energy
b. carbon dioxide
c. oxygen
d. water vapor

Answer 1

Carbon dioxide absorbs infrared energy (heat) and prevents some of it from being radiated into space. 
Water vapor reflects light back to the earth, again preventing energy from being radiated into space.
   
          Final Answer:Energy

Answer 2

A energy is the correct answer hope this helps