For the code below, show the stack with all activation record instances when execution reaches position $1$ in the following skeletal program.

program main$\{$

int X$,$ Y;

procedure A $($int P$,$ int Q$)\{$

int Z;

procedure B$()\{$

$...//$Position $1$

$\}$

procedure C$($int Q$)\{$

$...$

B$()$;

$...$

$\}$

$...$

C $($z$)$;

$...$

$\}$

$...$

A$($X$,$ Y$)$;

$...$

$\}$