following cryptographic object, which was sent to B by A in a recentprotocol:

$($NBKPrA mod NA $,\{|($NB$,$ NA$,\{(\{$K$\}$KPbB$,$ NA$)\}$xz mod NA$,\{|\{($M$,$ M$\text{'})\}$K$|\}$KPrS$)|\}$KPrA$)$

what must the values of the two variables, x and z$,$ be in order for B to gain access to M$\text{'}?$

$1-$ x$=$ NBKPrB mod NA and z $=$ KPrS

$2-$ x$=$ NAKPrB mod NB and z $=$ KPrA

$3-$ x$=$ NAKPrA mod NB and z $=$ KPrA

$4-$ x$=$ NAKPrA mod NB and z $=$ KPrB

$5-$ x$=$ NBNA mod NA and z $=$ NA

$6-$ x$=$ NBKPrB mod NA and z $=$ KPrB

$7-$ x$=$ NBKPrA mod NA and z $=$ KPrA

$8-$ x$=$ NBKPrA mod NA and z $=$ KPrS

$9-$ x$=$ NAKPrB mod NB and z $=$ KPrS

$10-$ x$=$ NBKPrB mod NA and z $=$ KPrA