Polymers

The given compound is a monomer unit of Teflon (polytetrafluoroethylene, PTFE), which is a polymer made by polymerizing tetrafluoroethylene. Teflon is known for its non-stick properties and its high chemical resistance. Nylon-6 is a different polymer, and Buna-S is a type of synthetic rubber, while Glyptol is a type of synthetic resin.

Bakelite is a well-known example of a thermosetting plastic. Thermosetting plastics are polymers that undergo a chemical change when heated, causing them to harden irreversibly. Polyethylene and PVC (polyvinyl chloride) are thermoplastics, meaning they soften and become moldable when heated and can be remolded. Therefore, Bakelite is the correct answer.