Alcohols can be distinguished from alkenes by

Out of the following,the alkene that exhibits optical isomerism is

Given below are two statements $:$
Statement $I :$ Ozonolysis followed by treatment with $Zn, H_2O$ of $cis-2-butene$ gives ethanal.
Statement $II :$ The product obtained by ozonolysis followed by treatment with $Zn, H_2O$ of $3,6-dimethyloct-4-ene$ has no chiral carbon atom.
In the light of the above statements,choose the correct answer from the options given below.

Identify the type of the given reactions:
$(a) \ CH_3CH_2OH \xrightarrow[\Delta]{\text{Conc. } H_2SO_4} CH_2 = CH_2 + H_2O$
$(b) \ CH_2BrCH_2Br + Zn \xrightarrow{\Delta} CH_2 = CH_2 + ZnBr_2$
$(c) \ CH_3CHBr - CH_2Br + Zn \xrightarrow{\Delta} CH_3CH = CH_2 + ZnBr_2$
$(d) \ RC \equiv CR' + H_2 \xrightarrow{Na, \text{liquid } NH_3} RCH = CHR'$
$(e) \ CH_3CH_2Cl + KOH \xrightarrow{\text{ethanol, } KOH} CH_2 = CH_2 + KCl + H_2O$

In the reaction sequence:
$Cyclohexane$ $\xrightarrow{hv/Cl_2} (X)$ $\xrightarrow{alc. KOH/\Delta} (Y)$ $\xrightarrow[(ii) H_2O/Zn]{(i) O_3} (Z)$
$(Z)$ will be :

For the reaction: $CH_2=CH-CH=CH_2 + HBr (1 \text{ eq}) \xrightarrow{80^{\circ}C} P_1 + P_2$ (where $P_1$ is the major product),identify $P_1$.