The petrol having octane number $80$ has

Octane number can be changed by

An organic compound $C_4H_6$ on ozonolysis gives $HCHO$,$CO_2$,and $CH_3CHO$. The compound will be:

$2, 4$-hexadiyne $(CH_3-C\equiv C-C\equiv C-CH_3)$ is allowed to react with $Li$ in $NH_3$ $(liq)$. The product obtained is treated with $1$ equivalent of $Cl_2$ in $CCl_4$. Which of the following constitutional isomers are possible products?

The end product formed in the above reaction is:

Arrange the stability of the given gem-diols in decreasing order:
$I$: Cyclopropane$-1,1-$diol
$II$: Cyclobutane$-1,1-$diol
$III$: Cyclopentane$-1,1-$diol