Consider the ${\mathrm{S}}_{\mathrm{N}}1$ solvolysis of the following halides in aqueous formic acid:

Which one of the following is correct sequence of the halides given above in the decreasing order of their reactivity?

The increasing order of reactivity of the following compounds towards reaction with alkyl halides directly is:

$\left(i\right)$

$\left(ii\right)$

$\left(iii\right)$

$\left(iv\right)$

The major product of the following reaction is:

The major product of the following reaction is:

The major product of the following reaction is:

In the reaction