The structure of Neoprene is:

Neoprene is obtained by the polymerisation of chloroprene. Chloroprene is $$2\text{-chloro-}1,3\text{-butadiene},\, CH_2=C(Cl)\!-\!CH=CH_2$$.

Step 1 - Write the monomer
The monomer is $$CH_2=C(Cl)\!-\!CH=CH_2$$. It possesses two conjugated double bonds at positions $$1$$ and $$3$$.

Step 2 - Type of addition
Dienes normally polymerise by $$1,4$$-addition. In $$1,4$$-addition the terminal carbon atoms $$1$$ and $$4$$ of the diene link with neighbouring monomer units, while the internal double bond disappears:

$$\begin{aligned} n\,CH_2=C(Cl)\!-\!CH=CH_2 \;\xrightarrow[\text{peroxide}]{\text{heat/\,emulsion}}\; [-CH_2\!-\!C(Cl)=CH\!-\!CH_2-]_n \end{aligned}$$

Step 3 - Write the repeating unit
Thus every repeating unit in neoprene is $$-CH_2\!-\!C(Cl)=CH\!-\!CH_2-$$. This is the characteristic $$\text{polychloroprene}$$ chain.

Step 4 - Match with the given options
Among the four displayed structures, the one showing the backbone
$$[-CH_2\!-\!C(Cl)=CH\!-\!CH_2-]_n$$ (polychloroprene) corresponds to Option C (Option 3 in the list).

Therefore, the correct answer is Option C (Option 3).