What subnet mask is represented by the slash notation $/20?$

radio$\_$button$\_$unchecked

$255\mathrm{.}255\mathrm{.}255\mathrm{.}248$

radio$\_$button$\_$unchecked

$255\mathrm{.}255\mathrm{.}224\mathrm{.}0$

radio$\_$button$\_$unchecked

$255\mathrm{.}255\mathrm{.}240\mathrm{.}0$

radio$\_$button$\_$unchecked

$255\mathrm{.}255\mathrm{.}255\mathrm{.}0$

radio$\_$button$\_$unchecked

$255\mathrm{.}255\mathrm{.}255\mathrm{.}192$