Given the following code, match what is exactly printed at each line.

public class M$1$P$1\{$

public static string $m1($string $str($

if $($str$.$ length $()==0)$

return $"\text{'}"$;

char $c=$ str$.$ charAt$()$;

if $(c==\text{'}x\text{'})$

return $\text{'}$ str$.$substring$(1))$;

$\}$

else return $.$substring$(1))$;

public static void main$($String args$[])\{$

$//$Line $1$ of output

System.out.println$($m$1("$Bob$")+1)$;

$//$Line $2$ of output

System, out.println$($m$1("$Fox$")+2)$;

$//$Line $3$ of output

System.out.println$($m$1("$Trix are for young kids"$)+3)$;

$//$Line $4$ of output

system.out.println$($m$1("")+4)$;

$\}$

$]$

$\}.$

$\}$

Line $1$

Line $2$

Line $3$

Line $4$