Concept:A polymer is a huge molecule formed by repeating smaller units called monomers.
Monomers join in long chains to give the polymer its structure.
Explanation:Rubber is a natural polymer made from many isoprene units repeated many times.
Starch is a polymer of glucose units linked together in long chains.
Proteins are polymers whose monomers are amino acids joined by peptide bonds.
So all three are genuine polymers because they contain many repeated units.
Fats, however, are not polymers.
Fats are triglycerides formed from one glycerol molecule and three fatty acid molecules.
They have a fixed structure instead of a chain of repeating monomers.
The absence of repeated monomer units means fats do not fit the definition of a polymer.
Hence, fats are the exception among the listed organic compounds.
Answer:D. fats