Which electron configuration represents the ground state of ions playing vital roles in biochemical processes?

A) 1s² 2s² 2p⁶ 3s¹ (Na^+)
B) 1s² 2s² 2p⁶ (Mg^2+)
C) 1s² 2s² 2p⁶ 3s² (Na^+)
D) 1s² 2s² 2p⁶ (Na^+)
E) 1s² 2s² 2p⁶ 3s² (Mg^2+)