Which statement causes overflow?

int x $=3000$;

int y $=1000$;

int z;

Group of answer choices

z $=($x $*$ x$)+($y $*$ y$)$;

z $=($x $*$ y$)+($x $*$ y$)+($x $*$ y$)$;

z $=$ x $*$ y $*$ y;

z $=$ x $*$ y;