A gas phase atom with the electronic configyartin

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(6)`

loses three electrons ,what is the electron configuration of the resulting gas phase ion ?

A. `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(5)`

B. `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)3d^(4)`

C. `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(3)`

D. `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)3d^(5)`