What is thermoplastic

thermoplastic is a type of plastic made up of polymer resins that becomes a soft material when it is heated and becomes hard when it is cooled. ... When thermoplastics are heated their physical property changes and they become a homogenized liquid and can be reshaped and resized.

denoting substances (especially synthetic resins) that become plastic on heating and harden on cooling, and are able to repeat these processes.

A thermoplastic, or thermosoft plastic, is a plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains are associated with intermolecular forces, which weaken rapidly with increased temperature, yielding a viscous liquid.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation:

ya the other dude is right