In which of the following polymers ethylene glycol is one of the monomer units?

Ethylene glycol is one of the monomer unit for the formation of glyptal polymer.By polymerization reaction between ethylene glycol and phthalic acid gives glyptal. Therefore option (i) is correct.

By using ethylene monomer we get (ii) polymer, therefore this is not thr correct answer.

Options (iii) and (iv) are also incorrect as they do not involve ethylene glycol as there monomer unit.