What is the organic product obtained when ethylene glycol is heated with acidified potassium permanganate?

The order of reactivity of $C_2H_6$,$C_2H_4$,and $C_2H_2$ is.......

Match the following reactions with their nature and choose the correct code.

Reaction	Nature of reaction
$A. RBr \xrightarrow{Na}$	$1. \text{Partial reduction}$
$B. RCOO^-Na^+ \xrightarrow{NaOH/CaO, \Delta}$	$2. \text{Electrophilic addition}$
$C. R-C \equiv C-R' \xrightarrow{\text{Lindlar's catalyst } (H_2)}$	$3. \text{Wurtz reaction}$
$D. H_2C=CH_2 \xrightarrow{Br_2/CCl_4}$	$4. \text{Decarboxylation}$
	$5. \text{Decarboxylative dimerisation}$

The cycloalkane $(X)$ on bromination consumes one mole of bromine per mole of $(X)$ and gives product $(Y)$ in which $C:Br$ ratio is $3:1$. The percentage of bromine in the product $(Y)$ is $ . . . . . . \%$ (Nearest integer).
(Given: Molar mass in $g \ mol^{-1}$, $H:1, C:12, O:16, Br:80$)

$CH_3-C(CH_3)=CH_2 + (CH_3)_3CH \xrightarrow[273 \ K]{HF} C_8H_{18} (A)$
Unknown $(A)$ in the above reaction is:

The petrol having octane number $80$ has