Which line$($s$)$ if any might crash when calling these functions in a multi$-$threaded program?if $($iter$)\{$ lock$($&mutex$)$; unlock$($&mutex$)$;$\}$

$\}$

void$*$ iter$\_$get$($iter$\_$t$*$ iter$)\{$ if $($iter$->$curr$)\{$ void$*$ obj $=$ iter$->$curr$->$obj; return obj;$\}\}$Lines $3$&$12$

Line $3$

Line $5$

Line $14$

Lines $5$&$14$

Lines $12$ & $14$

No crashes