Concept:Condensation polymers form by linking monomers with the elimination of a small molecule, such as water.
Explanation:Nylon is a condensation polymer formed from dicarboxylic acid and diamine.
Protein is a condensation polymer of amino acids, with water released during peptide bond formation.
Starch is a condensation polymer of glucose units, eliminating water molecules during glycosidic bond formation.
Polyethene, however, is formed by addition polymerisation of ethene monomers.
In addition polymerisation, no small molecule is eliminated and no condensation reaction occurs.
Therefore, polyethene is not a condensation polymer.
Answer:D. polyethene