For hydrogen atom and one electron species, the energy of orbitals is decided by the value of principal quantum number. Higher the value of principal quantum number, higher will be the energy of orbital. (A) 4 s  n=4 (B)3px  n=3 (C)3dx2−y2  ‌ n = ‌3 (D)3dz2  n=3 (E)4pz  n=4 ∴ (B), (C) and (D) have orbitals with the lowest energy.