Im just guessing so i think its a
Http://www.biocab.org/Carbon_Dioxide_CO2.html
A polymer is made up of monomers. A monomer is a unit that occurs in repetitive chains. Lipids do not occur in repetitive chains, so they are not classified as monomers. Since they're not monomers, they can't make up polymers, either.
I think the answer is c because the cooler summers help cool down the earth preventing global warming