In which of the following case '$\mathrm{H}$' shift is more preferable than '${\mathrm{CH}}_3$' shift

Pyrrole is treated of with alkaline chloroform to form two products $\mathrm{A}$ and $\mathrm{B}$

Which of the following intermediates is likely to be formed?

(I)

(II)

(III)

(IV)

The order of decreasing ${\mathrm{S}}_{\mathrm{N}}1$ reactivities of the halides 

$$\begin{gathered} {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CI} \\ \mathrm{I} \end{gathered}$$

$$\begin{gathered} {\mathrm{CH}}_2={\mathrm{CHCHCICH}}_3 \\ \mathrm{II} \end{gathered}$$

$$\begin{gathered} {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CHCICH}}_3 \\ \mathrm{III} \end{gathered}$$

Which is/ are true statement(s):

Most stable free radical formed at the position