Polymer Structure Matching

Steps:

• Identify the monomer's functional groups that form linkages in polymerization.
• Examine each diagram for repeating units connected via those linkages.
• Check for partial chain representation without end groups dominating.
• Select the diagram showing the correct repeating polymer backbone.

Why D is correct:

• D depicts the repeating monomer units linked by condensation bonds, matching the definition of a partial polymer structure as a chain segment.

Why the others are wrong:

• A shows isolated monomers, not linked into a chain.
• B displays a cyclic structure, not a linear polymer.
• C illustrates a complete small molecule, lacking polymer repetition.

Final answer: D