What is the Double Bond Equivalent $(DBE)$ of $(A)$?

Two unknown compounds $X$ and $Y$,both having molecular formula $C_4H_8O$,give the following results with four chemical tests.

Compound	Bromine	$Na$ metal	Chromic acid	Lucas reagent
$X$	decolourises	bubbles	Orange to Green	No reaction
$Y$	No reaction	No reaction	No reaction	No reaction

Compound $X$ and $Y$ respectively are:

The exact order of acidity of the compounds $p-$nitrophenol, acetic acid, acetylene and ethanol is

How many secondary carbon and hydrogen atoms are present in the molecule $CH_3-CH(Br)-CH(Br)-CH_3$ respectively?

Vanillin,a compound obtained from vanilla beans,has a total sum of oxygen atoms and $\pi$-electrons equal to . . .

Given below are two statements:
Statement-$I$ : Compound $(X)$, shown below, dissolves in $NaHCO_3$ solution and has two chiral carbon atoms.
Statement-$II$ : Compound $(Y)$, shown below, has two carbons with $sp^3$ hybridization, one carbon with $sp^2$ and one carbon with $sp$ hybridization.
In the light of the above statements, choose the correct answer from the options given below: