Which of the following statements is not correct?
A. `La(OH)_(3)` is less basic than `Lu(OH)_(3)`.
B. In lanthanide series ionic radius of `Ln^(3+)` ions decreases.
C. La is actually an element of transition series rather than lanthanide series.
D. Atomic radii of Zr and Hf are same because of lanthanide contraction.