The incorrect statement for lanthanides among the following statements is

A

4f and 5d orbitals are so close in energy that it is very difficult to locate the exact position of electrons in lanthanides

B

most common stable oxidation state is +3

C

tripositive lanthanide ions have characteristic color depending on nature of group with which they combine to form compounds

D

some lanthanide ions absorb either in infrared or ultraviolet region of electromagnetic spectrum