Which of the following is an example of a thermosetting polymer?

Which of the following is an incorrect match for the pair of $\text{Polymer} - \text{Monomer}$?

$A$ polymer with high chemical stability has a melting point $(M.P.)$ of $327\ ^\circ C$ and the density of a completely crystalline sample is $2.3\ g/cm^3$. It is:

The ‘mercerised cellulose’ is chemically prepared by

The polymer Buna-$S$ is made of .....

Synthetic fibres like nylon-$66$ are very strong because