Hydrolysis of an alkyl bromide $X$ $(C_5H_{11}Br)$ follows first-order kinetics. Reaction of $X$ with $Mg$ in dry ether followed by treatment with $D_2O$ gives $Y$. What is $Y$?

Given below are two statements $:$
Statement $(I) :$ Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction.
Statement $(II) :$ In alcoholic potassium hydroxide,alkyl chlorides form alkenes by abstracting the hydrogen from the $\beta-$carbon.
In the light of the above statements,choose the most appropriate answer from the options given below $:$

Given below are two statements:
Statement-$I$: High concentration of strong nucleophilic reagent with secondary alkyl halides which do not have bulky substituents will follow $S_{N}2$ mechanism.
Statement-$II$: $A$ secondary alkyl halide when treated with a large excess of ethanol follows $S_{N}1$ mechanism.
In the light of the above statements,choose the most appropriate from the options given below:

Which of the following alkyl halides has the highest boiling point?

The one giving the maximum number of isomeric alkenes on dehydrohalogenation reaction is (excluding rearrangement):

Identify $A$ and $B$ in the following reactions:
$A \xrightarrow[\Delta]{aq. NaOH} C_2H_5OH \xleftarrow{AgOH} B$