Which one of the following structures represents nylon $6, 6$ polymer?

Match List-$I$ with List-$II$ :
| List-$I$ | List-$II$ |
| :--- | :--- |
| $(a)$ Chloroprene | $(i)$ $CH_2=C(CH_3)-CH=CH_2$ |
| $(b)$ Neoprene | (ii) $CH_2=C(Cl)-CH=CH_2$ |
| $(c)$ Acrylonitrile | (iii) $[-CH_2-C(Cl)=CH-CH_2-]_n$ |
| $(d)$ Isoprene | (iv) $CH_2=CH-CN$ |
Choose the correct answer from the options given below :

Match List-$I$ with List-$II$:

List-$I$ (Polymer)	List-$II$ (Nature)
$A$. $(-CH_2-C(Cl)=CH-CH_2-)_n$	$I$. Thermosetting polymer
$B$. $(-NH-(CH_2)_6-NH-CO-(CH_2)_4-CO-)_n$	$II$. Fibers
$C$. $(-CH_2-CH(Cl)-)_n$	$III$. Elastomer
$D$. $(-C_6H_3(OH)-CH_2-)_n$	$IV$. Thermoplastic polymer

Choose the correct answer from the options given below.

What is the structural difference between $HDP$ and $LDP$? How does the structure account for their different behavior,nature,and usage?

Which is not a monomer for a high molecular mass silicone polymer?

Bakelite is a type of .......