Match species given in column I with the electronic configuration given in column II.

Explanation

`Ararr4Brarr3Crarr1Drarr2`
A. `Cr(Z=24)=1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)=[Ar]3d^(5)4s^(7)`
B. `Fe^(2+)(Z=26)= 1s^(2)2 s^(2)2p^(6)3s^(2)3p^(6)3d^(6)4s^(6)=[Ar]3d^(6)4s^(0)`
C. `Ni^(2+)(Z=28)= 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(6)4s^(0)=[Ar]3d^(8)4s^(0)`
D. `Cu(Z=29)=1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)2s^(-1)=[Ar]3d^(10)4s^(1)`