What will be the output of the program $?$

int main$()$

$\{$

int $x=30,**y,**z$;

$y=$&$x$; $/*$ Assume address of $x$ is $500$ and integer is $4$ byte size $*/$

$z=y$;

$**y++=**z++$;

$x++$;

printf$("$x$=\%$d$,y=\%d,z=\%\frac{d}{?}$

$,x,y,z$;

return $$;

$\}$

a$.x=31,y=502,z=502$

b$.x=31,y=504,z=504$

C$.x=31,y=500,z=500$

d$.$ none

e$.x=31,y=498,z=498$