$(11)$ why are polar solutions better suited for $S{N}_1$ reactions?

$($a$)$ they dissolve compounds more efficiently. $($b$)$ they boil at higher temperature

$($c$)$ they are mure optically active

$($d$)$ they stabalize the cationic intermediates

$(12)$ Given the unknown compound $(C_4{H}_8,C{l}_2)$ which structure is mos$-1$ consistent with H$-$NMR spectrum provided?

$($a$)$

$(b)$

$($C$)$