Which among the following is a thermoplastic polymer ?

Thermoplastic polymer - Those plastics which can be remoulded again and again. Thermosetting plastics - Those plastics which becomes hard on cooling and permanently sets into a solid. (1) Bakelite - Thermosetting plastic polymer (A phenol - formaldehyde resin) (2) Polythene - Thermoplastic polymer. (3) Urea - formaldehyde resin - A thermosetting plastic polymer. (4) Melamine polymer - Thermosetting plastic polymer.