var x ;

function sub$1()\{$

document.write$("$x $="+$ x $+"")$;

$\}$

function sub$2()\{$

var x ;

$x=8$;

sub$1()$;

$\}$

$x=10$;

sub$2()$;

Under dynamic$-$scoping rules, what value of $x$ is displayed in function sub$1?$

$0$

$8$

$10$

$18$