Ions and ionic bonds — practice question

When a Group I element reacts with a Group VII element, an ionic bond is formed. Which row illustrates the changes in electronic structures?

• AGroup I: before $2,8,1$, after $2,8,2$; Group VII: before $2,7$, after $2,6$
• BGroup I: before $2,8$, after $2,7$; Group VII: before $2,8$, after $2,8,1$
• CGroup I: before $2,8,1$, after $2,8$; Group VII: before $2,7$, after $2,8$
• DGroup I: before $2,8$, after $2,8,1$; Group VII: before $2,8$, after $2,7$