b
(b) \(\underset{\,\,\,\,\,\,\,\,\,{{3}^{o}}}{\mathop{C{{H}_{3}}-\underset{C{{H}_{3}}}{\overset{\,\,C{{H}_{3}}}{\mathop{\underset{|\,\,\,\,\,}{\overset{|\,\,\,\,}{\mathop{{{C}^{+}}\,}}}\,}}}\,>}}\,\,\underset{\,\,\,\,\,\,\,\,\,\,\,2{}^\circ }{\mathop{C{{H}_{3}}-\underset{C{{H}_{3}}}{\mathop{\underset{|\,\,\,\,\,\,}{\mathop{CH{{_{{}}^{{}}}^{+}}}}\,}}\,>}}\,\,\underset{\begin{matrix}
   \begin{matrix}
   {}  \\
   \begin{matrix}
   {}  \\
   {{1}^{o}}  \\
\end{matrix}  \\
\end{matrix}  \\
   \,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
\end{matrix}}{\mathop{C{{H}_{3}}-CH{{_{2}^{{}}}^{+}}}}\,>\underset{\begin{matrix}
   {}  \\
   \begin{matrix}
   {}  \\
   \begin{smallmatrix} 
 \text{Methyl } \\ 
 \text{carbocation} 
\end{smallmatrix}  \\
\end{matrix}  \\
\end{matrix}}{\mathop{CH{{_{3}^{{}}}^{+}}\,\,\,\,\,\,\,}}\,\)

The higher the number of alkaline groups, the greater the charge is the deflection and hence the more carbonium ion is permanent.