The major product '$Y$' in the following reaction is

The correct order of reactivity of $CH_3Br$ in methanol with the following nucleophiles is:
$F^{-}, I^{-}, C_2H_5O^{-}$ and $C_6H_5O^{-}$

The following bimolecular elimination reaction $(E_2)$ is carried out with different halogen leaving groups. The per cent yield of the two products ($2$-hexene and $1$-hexene) for each leaving group is listed below.

Leaving group	Conj. Acid $pK_a$	$\%$-yield of $2$-hexene	$\%$-yield of $1$-hexene
$X = I$	$-10$	$81\%$	$19\%$
$X = Br$	$-9$	$72\%$	$28\%$
$X = Cl$	$-7$	$67\%$	$33\%$
$X = F$	$3.2$	$30\%$	$70\%$

Which of the following statement$(s)$ is/are true concerning this series of $E_2$ reactions?

The relation between $(A)$ and $(B)$ is:

The major product in the given reaction is:

Which among the following alkyl halides gives more than one product upon dehydrohalogenation?