Choose the correct metal/ ion from the brackets which -----------------------------
(A) has chemical reactivity similar to that of the first few members of the Lanthanoids (Zn, Ca, Fe, Cu).
(B) has stable \( 4f^7 \) electronic configuration, but acts as a strong reducing agent and converts to \( M{3+} \) state. \(Eu^{2+}, Ce^{2+}, Pr^{2+}, Dy^{2+}\)
(C) is a colorless ion (Tm^{3+}, Lu^{3+}, Gd^{3+}, Sm^{3+}).
(D) shows stable +2 oxidation state and is diamagnetic (Ce, Sm, Ho, Yb).