Which from following is a polyester fibre?

Step-by-step solution

Identifying the polyester fiber: The ester functional group defines polyesters, which are polymers containing repeating ester units in their main chain. Option A, PHBV (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)), is a biodegradable copolymer formed from hydroxy acids. Its structure contains ester linkages, confirming it as a polyester. Option B, urea formaldehyde, is an amino resin produced from urea and formaldehyde condensation, lacking ester bonds. Option C, thermocol (expanded polystyrene), is a vinyl polyme