Knowing that the chemistry of lanthanoids (Ln) is dominated by its +3 oxidation state, which of the following statements is incorrect

(a) Because of the large size of the Ln(III) ions, the bonding in its compounds is predominantly ionic in character.

(b ) The ionic sizes of Ln(III) decrease in general with increasing atomic number.

(c) Ln(III) compounds are generally colourless.

(d) Ln(III) hydroxides are mainly basic in character.