Identify homopolymer from following.

Thermocol, also known as expanded polystyrene (EPS), is a homopolymer. A homopolymer is a polymer that is composed of only one type of monomer unit repeated throughout its structure. In the case of thermocol, the repeating unit is the styrene monomer. When polymerized, styrene forms a long chain known as polystyrene, which is used in a variety of applications, including packaging materials like thermocol.
Here's a brief description of each option to clarify why the others are not homopolymers:
Polycarbonate (Option A): Polycarbonate is a copolymer commonly made from bisphenol A and phosgene, thus it's not a homopolymer.
Buna-N (Option B): Buna-N, also known as nitrile rubber, is a copolymer made from butadiene and acrylonitrile.
Glyptal (Option C): Glyptal is a copolymer derived from reaction between glycerol and phthalic anhydride, classifying it as a copolymer.