For the Lanthanides
A. Lanthanides display only the (+3) oxidation state.
B. Oxidation numbers (+2) and (+4) occur when they lead to a noble gas configuration.
C. Oxidation numbers (+2) and (+4) are observed when they lead to a half-filled orbital.
D. $$Yb^{2+}$$ has a completely filled f-orbital

Choose the correct answer from the option given below:

A

A only

B

B and C only

C

C and D only

D

B, C and D only