Which of the following polymers have vinylic monomer units?

now let’s understand what Vinylic monomer means. They are basically a monomer containing a carbon-carbon double bond in them.

Vinyl group looks as follows

Acrilan, Polystyrene and Teflon preparation looks as follows:

Nylon preparation looks as follows:

With the above images we can conclude that option I, ii and Iv stand right for the question.