Match List I with List II

Choose the correct answer from the options given below:

Given below are two statements :

Statement I : Ethene at 333 to $$343 \mathrm{~K}$$ and $$6$$-$$7$$ atm pressure in the presence of $$\mathrm{AlEt}_{3}$$ and $$\mathrm{TiCl}_{4}$$ undergoes addition polymerization to give LDP.

Statement II : Caprolactam at $$533$$-$$543 \mathrm{~K}$$ in $$\mathrm{H}_{2} \mathrm{O}$$ through step growth polymerizes to give Nylon 6.

In the light of the above statements, choose the correct answer from the options given below:

The polymer $$\mathrm{X}$$ - consists of linear molecules and is closely packed. It is prepared in the presence of triethylaluminium and titanium tetrachloride under low pressure. The polymer $$\mathrm{X}$$ is-

Buna-S can be represented as: