The electronic configuration of Eu ³⁺ ion is:

The electronic configuration of gadolinium (Atomic number 64) is
(a) $\left[Xe\right]4f^{3}5d^{5}6s^2$
(b) $\left[Xe\right]4f^{7}5d^{2}6s^1$
(c) $\left[Xe\right]4f^{7}5d^{1}6s^2$
(d) $\left[Xe\right]4f^{8}5d^{6}6s^2$

The electronic configuration of Gd²⁺ is (at. No. of Gd is 64)

The element with the electronic configuration $\left[Xe\right]4f^{14}5d^{1}6s^2$ is a: