Using the following program, at which line$($s$)$ of code will a buffer overflow condition occur?

$$

$1$ int main$($int argc, char $*$argv$[])\{$

$2$ char str$1[10]$;

$3$ char str$2[10]$;

$4$ next$\_$tag$($str$1)$;

$5$ gets$($str$2)$;

$6$ printf$($str$1(\%$s$),$ str$2(\%$s$)$

$$ str$1,$ str$2)$;

$$

$7\}$

$$

Line $4$

Line $5$

Line $6$

Lines $4$ and $5$

Lines $5$ and $6$

Lines $4,5,$ and $6$

None of the above