Suppose we have the following thread to return long value to the parent thread

void $*$return$\_$long$\_$thread$($void $*$arg$)\{$

long n$1=0$;

static long n$2=0$;

long $*$p$1=($long $)$malloc$($sizeof$($long$))$;

if $($p$1==$ NULL$)$ exit$()$;

$/$ some work is done and the same value is saved into n$1,$ n$2,$ and $*$p$1*/$

return$(\_\_\_\_\_\_)$;

$\}$

which of the following should be used as return statement to be safe in any circumstances?