Which of the following statements are correct?

$\mathrm{Gd}{}^{3+}$ is $4f^7$ (7 unpaired), $\mathrm{La}{}^{3+}$ is $4f^0$ and $\mathrm{Ce}{}^{4+}$ is $4f^0$, both without unpaired electrons and hence diamagnetic. $\mathrm{Lu}{}^{3+}$ is $4f^{14}$, completely paired and diamagnetic, so the last statement is wrong.