Identify thermoplastic polymer from following.

Polythene (Option C) is a thermoplastic polymer. Thermoplastics are materials that become pliable or moldable above a specific temperature and solidify upon cooling. They can be remelted and remolded multiple times without losing their chemical properties. Polythene, commonly known as polyethylene, is widely used in applications like packaging films, containers, and insulation for cables due to its flexibility, strength, and recyclability.
Urea formaldehyde resin (Option A) and Bakelite (Option B) are examples of thermosetting polymers, which harden permanently after being heated and cannot be remolded. Buna-N (Option D) is a synthetic rubber, not a thermoplastic.