Which of the following set of ions act as oxidising agents?

Options

1. A$\mathrm{Ce}^{4+}$ and $\mathrm{Tb}^{4+}$
2. B$\mathrm{La}^{3+}$ and $\mathrm{Lu}^{3+}$
3. C$\mathrm{Eu}^{2+}$ and $\mathrm{Yb}^{2+}$
4. D$\mathrm{Eu}^{2+}$ and $\mathrm{Tb}^{4+}$