Identify the correct statements about lanthanoids I. $\quad \mathrm{Ce}^{4+}$ and $\mathrm{Tb}^{4+}$ act as oxidising agents II. $\quad \mathrm{Eu}^{2+}$ and $\mathrm{Yb}^{2+}$ act as oxidising agents III. Mischmetal is an alloy of $95 \%$ iron and $5 \%$ lanthanoid metal IV. $\quad \mathrm{La}^{3+}$ and $\mathrm{Ce}^{4+}$ are diamagnetic in nature

• A

  I & II only
• Correct answer
  B

  I & IV only
• C

  II, III & IV only
• D

  I, II & IV only

Hence, the correct answer is option: 'B'.