A

\[1s^2 2s^2 2p^6 3s^2 3p^3\]

B

\[1s^2 2s^2 2p^4 3s^2 3p^4\]

C

\[1s^2 2s^2 2p^5\]

D

\[1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 4p^5\]

E

\[1s^2 2s^2 2p^6 3s^2 3p^5\]