The main reason for larger number of oxidation states exhibited by the actinoids than the corresponding lanthanoids, is :-

Options

A. More energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
B. Lesser energy difference between 5f and 6d orbitals than between 4f and 5d orbitals
C. Greater metallic character of the lanthanoids than that of the corresponding actinoids
D. More active nature of the actinoids

Answer

B