Ester linkage is a specific type of chemical bond that is formed between a carboxylic acid and an alcohol group. It is commonly found in polymers called polyesters. Among the given options, Terylene is the only one that contains ester linkage.

Terylene, also known as polyethylene terephthalate (PET), is a type of polyester. It is made by the condensation polymerization of terephthalic acid and ethylene glycol. In this process, the carboxylic acid group of terephthalic acid reacts with the alcohol group of ethylene glycol, forming an ester linkage.

Here is a detailed explanation of the options and why Terylene has an ester linkage:

a) Nylon: Nylon is a synthetic polymer that belongs to a class of polymers called polyamides. It is made by the condensation polymerization of a dicarboxylic acid and a diamine. The linkage formed in nylon is an amide linkage, not an ester linkage. Therefore, nylon does not have an ester linkage.

b) Bakelite: Bakelite is a type of thermosetting plastic that is made by the condensation polymerization of phenol and formaldehyde. The linkage formed in Bakelite is a phenyl-methylene linkage, not an ester linkage. Therefore, Bakelite does not have an ester linkage.

c) Terylene: Terylene, also known as PET, is a type of polyester. It is made by the condensation polymerization of terephthalic acid and ethylene glycol. The carboxylic acid group of terephthalic acid reacts with the alcohol group of ethylene glycol, forming an ester linkage. Therefore, Terylene has an ester linkage.

d) PVC: PVC, or polyvinyl chloride, is a type of vinyl polymer. It is made by the polymerization of vinyl chloride monomers. The linkage formed in PVC is a vinyl linkage, not an ester linkage. Therefore, PVC does not have an ester linkage.

In summary, among the given options, Terylene is the only one that contains an ester linkage.