Which of the following polymers does not involve $C-C$ bond formation during polymerization?

If the number average molecular weight and weight average molecular weight of a polymer are $40000$ and $60000$ respectively, the polydispersity index of the polymer will be

The mass average molecular mass and number average molecular mass of a polymer are respectively $40,000$ and $30,000$. The polydispersity index of the polymer will be:

The monomer of Teflon is

Identify the thermosetting polymer from the following.

The correct match between Item-$I$ and Item-$II$ is

Item-$I$	Item-$II$
$(a)$ High density polythene	$(I)$ Peroxide catalyst
$(b)$ Polyacrylonitrile	$(II)$ Condensation at high temperature and pressure
$(c)$ Novolac	$(III)$ Ziegler-Natta catalyst
$(d)$ Nylon-$6$	$(IV)$ Acid or base catalyst