Which line$($s$)$ if any might crash when calling these functions in a multi$-$threaded program?if $($iter$)\{$ if $($iter$->$curr$)\{\}\}$

$\}$

void$*$ iter$\_$get$($iter$\_$t$*$ iter$)\{$ lock$($&iter$->$mutex$)$; void$*$ obj $=$ iter$->$curr$->$obj; return obj; unlock$($&iter$->$mutex$)$;return NULL;

$\}$Lines $4$ & $13$

Line $4$

Line $5$

Line $14$

Lines $5$ & $14$

Lines $13$ & $14$

No crashes