Concept:
Biodegradable polymers are polymers that can be broken down by microorganisms into simpler substances like \(CO_2\), water, etc.
Step 1: Identify biodegradable polymer type.
A well-known biodegradable polymer is:
\[
\text{PHBV (Poly-}\beta\text{-hydroxybutyrate-co-}\beta\text{-hydroxyvalerate)}
\]
Step 2: Monomers of PHBV.
• 3-hydroxybutanoic acid
• 3-hydroxypentanoic acid
Step 3: Check options.
• (A) Urea-formaldehyde → thermosetting → non-biodegradable
• (B) Ethylene glycol + terephthalic acid → PET → non-biodegradable
• (C) Given monomers → form PHBV → biodegradable ✓
• (D) Phenol-based → not biodegradable
• (E) Nylon-6,6 → non-biodegradable
Final Conclusion:
\[
\boxed{\text{Option (C) forms biodegradable polymer}}
\]