How many elements are in $($i$.$e$.,$ what is the size of$)$ the following set:

$\{$

$\{$

$\}$

$\}$

$\{\{\}\}$

$($Select the one best answer$)$

Choice $1$ of $4$:zero

Choice $2$ of $4$:one

Choice $3$ of $4$:two

Choice $4$ of $4$:three