[单选题]
A neutral atom has an electrf uiewn23/4y19ls uvvon configuration o4by6wa qm8 v-*mjpu l(f $1s^22s^22p^6$. If a neutral atom holds one additional electron, what is the ground state configuration?
A. $1s^22s^22p^63s^1$
B. $1s^22s^22p^7$
C. $1s^22s^32p^6$
D. none of the given answers
