In which of the following species,addition of $H^{+}$ will be faster in comparison to other three species?

Identify the major product $A$ in the following reaction.
$3-$Bromo$-2-$methylpentane $\xrightarrow{alc. KOH} A$

In hydroboration reaction:
$I$. $Syn$ addition takes place
$II$. Reaction proceeds through formation of a cyclic transition state
$III$. Markovnikov rule is followed in the reaction
$IV$. Anti-addition takes place and anti-Markovnikov rule is followed
Which statement$(s)$ is/are correct?

Which of the following is the major product in the following reaction?

The reaction of $4$-methyloct$-1-$ene $(P, 2.52 \ g)$ with $HBr$ in the presence of $(C_6H_5CO_2)_2O_2$ gives two isomeric bromides in a $9:1$ ratio,with a combined yield of $50 \%$. Of these,the entire amount of the primary alkyl bromide was reacted with an appropriate amount of diethylamine followed by treatment with aqueous $K_2CO_3$ to give a non-ionic product $S$ in $100 \% $ yield. The mass (in $mg$) of $S$ obtained is. . . . . . . [Use molar mass (in $g \ mol^{-1}$) : $H=1, C=12, N=14, Br=80$]

Ozonolysis of $2$-methylbut-$2$-ene yields