What is the ground state electronic configuration for the Cu atom?

A

$$1s^{2} 2s^{2} 2p^{2} 3s^{2} 3p^{6} 3d^{9} 4s^{2}$$

B

$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{1}$$

C

$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{8} 4s^{3}$$

D

$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{9} 4s^{1} 4p^{1}$$