Monomers link together to make polymers. Examples of monomer-polymer pairs:
Monomer: Amino acids
Polymer: Proteins
Monomer: Nucleotide
Polymer: DNA (and RNA)
Monomer: Monosaccaride
Polymer: Polysaccharide
Note the prefixes of these words. Mono- means "one" and poly- means "many". The "ones" (monomers) make up the "many" (polymers).
Answer:
A. polymer