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

Question

( A ) Ln (III) compounds are generally colourless
( B ) Because of the large size of the Ln (III) ions the bonding in its compounds is predominantly ionic in character.
( C ) Ln (III) hydroxides are mainly basic in character
( D ) The oinic sizes of Ln (III) ions the bonding in its compounds is predominantly ionic in character