کدام یک افرازی برای مجموعهٔ $\left\{ \varnothing ,\left\{ \varnothing ,\left\{ \varnothing \right\} \right\},\left\{ \varnothing \right\} \right\}$ است؟
1 )
$\left\{ \varnothing \right\},\left\{ \varnothing ,\left\{ \varnothing ,\left\{ \varnothing \right\} \right\} \right\}$
2 )
$\left\{ \left\{ \varnothing \right\} \right\},\left\{ \left\{ \varnothing ,\left\{ \varnothing ,\left\{ \varnothing \right\} \right\} \right\} \right\}$
$\left\{ \left\{ \varnothing \right\} \right\},\left\{ \varnothing ,\left\{ \varnothing ,\left\{ \varnothing \right\} \right\} \right\}$
4 )
$\left\{ \left\{ \, \right\} \right\},\left\{ \varnothing ,\left\{ \varnothing ,\left\{ \varnothing \right\} \right\} \right\}$