The most common oxidation state of Lanthanoid elements is \( +3 \). Which of the following is likely to deviate easily from \( +3 \) oxidation state?
\( \mathrm{Ce} \) (\( \mathrm{At.\ No.\ }58 \))
\( \mathrm{La} \) (\( \mathrm{At.\ No.\ }57 \))
\( \mathrm{Lu} \) (\( \mathrm{At.\ No.\ }71 \))
\( \mathrm{Gd} \) (\( \mathrm{At.\ No.\ }64 \))