(a)$\mathrm{D}_{3h}; \mathrm{d}_{x^2-y^2} > \mathrm{d}_{z^2} > \mathrm{d}_{xy} > \mathrm{d}_{xz}, \mathrm{d}_{yz}$
(b)$\mathrm{D}_{3d}; \mathrm{d}_{z^2} > \mathrm{d}_{xy}, \mathrm{d}_{x^2-y^2} > \mathrm{d}_{xz}, \mathrm{d}_{yz}$
(c)$\mathrm{D}_{3d}; \mathrm{d}_{x^2-y^2} > \mathrm{d}_{z^2}, \mathrm{d}_{xy} > \mathrm{d}_{xz}, \mathrm{d}_{yz}$
(d)$\mathrm{D}_{3h}; \mathrm{d}_{z^2} > \mathrm{d}_{x^2-y^2}, \mathrm{d}_{xy} > \mathrm{d}_{xz}, \mathrm{d}_{yz}$