What is the major product obtained in the following reaction?

The correct order of increasing reactivity of $C-X$ bond towards nucleophile in the following compounds is:
$I$: Chlorobenzene (or aryl halide)
$II$: $2,4$-Dinitrochlorobenzene
$III$: $(CH_3)_3C-X$ ($3^o$ alkyl halide)
$IV$: $(CH_3)_2CH-X$ ($2^o$ alkyl halide)

Which of the following products can be obtained from the above reaction?

In the given reaction,$[X]$ will be:

What is the product of the following 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.