What must the values of the variables, x$,$ y and z be in the following object:

$($z$,\{$x$\}$y$)$

in order for the digital signature to be validated by the key:

KpbBob

$1-$ z$=$M and x$=$KpbBob and y$=$KprBob

$2-$ z$=$KpbBob and x$=$M and y$=$KprBob

$3-$ z$=$KprBob and x$=$Hash$($M$)$ and y$=$M

$4-$ z$=$M and x$=$M and y$=$KprBob

$5-$ z$=$M and x$=$Hash$($M$)$ and y$=$KprBob