Which of the following 3d-orbitals has electron density in three axes ?       

 ${\mathrm{d}}_{{\mathrm{z}}^2}$ -orbital has one lobe along z-axis and donut-shaped electron cloud perpendicular to it in xy plane, while all other d-orbitals have two dumbells eiher along the axis (${\mathrm{d}}_{{\mathrm{x}}^2-{\mathrm{y}}^2}$​) or in between the axis (d_xy​, d_yz​, d_zx​)