In context of the lanthanoids, which of the following statements is not correct?

Options

A. There is a gradual decrease in the radii of the members with increasing atomic number in the series
B. All tha number exhibit `+3` oxidation state
C. Because of similar properties the separation of lanthanoids is not easy
D. Availability of 4f electrons results in the formation of compound in `+4` state for all the members of the series

Answer

D

Explanation

Availability of 4f electrons do not results in the formation of compounds in `+4` state for all the members of the series.