ITN $($Version $7\mathrm{.}00)-$ IP Addressing Exam

$12$ Given IPv$6$ address prefix $2001$:db$8$::$/48,$ what will be the last subnet that is created if the subnet prefix is changed to $/52?$

$2001$:db$8$:$0$:$8000$:$/52$

$2001$:db$8$:$0$:f$00$:$/52$

$2001$:db$8$:$0$:f$000$::$/52$

$2001$:db$8$:$0$:$/52$