Alkyl halide $\xrightarrow[\text{Ether}]{Mg}$ Grignard Reagent $\xrightarrow{H_2O}$ Propane,then alkyl halide may be :-

Identify the correct order of reactivity for the following pairs towards the respective mechanism:
$(A)$ $S_{N}2$: Isobutyl bromide > tert-Butyl bromide
$(B)$ $S_{N}1$: Benzyl bromide > $2-$Phenylethyl bromide
$(C)$ Electrophilic substitution: Chlorobenzene > $1-$Chloro$-4-$nitrobenzene
$(D)$ Nucleophilic substitution: Bromobenzene < $1-$Bromo$-4-$nitrobenzene
Choose the correct answer from the options given below:

What is the product of the reaction?

$(Z)-2$-Butene reacts with $Br_2/H_2O$. The resulting bromohydrin when treated with methoxide in methanol undergoes an intramolecular $S_N2$ reaction. Taking into consideration the stereochemical consequences of the reaction mechanism involved, choose the final product$(s)$ of these transformations.

Assertion : Alkylbenzene is not prepared by Friedel-Crafts alkylation of benzene.
Reason : Alkyl halides are less reactive than acyl halides.

When $but-3-en-2-ol$ reacts with aqueous $HBr$,which of the following products is obtained?