The correct electronic configuration of Cu is ___________________?
A. [Ar]4s1
B. [Ar]4s2
C. [Ar]3d104s1
D. [Ar]3d94s2
A. [Ar]4s1
B. [Ar]4s2
C. [Ar]3d104s1
D. [Ar]3d94s2