Which of the following is not correct regarding $Terylene$?

Which of the following pairs is $NOT$ correctly matched?

$A$ 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:

Which of the following statements are correct?
$(1)$ Biodegradable polymers can be converted into essential life substances after degradation.
$(2)$ Non-biodegradable polymers are active towards environmental processes.
$(3)$ Non-biodegradable polymers can be converted into essential life substances.
$(4)$ $PHBV$ is degraded by bacteria under environmental conditions.

Which of the following is used to make rubber hard for tire manufacturing?

Write down the preparation and use of Buna-$N$.