Which group of the periodic table of elements forms only 1+ ions?

Question

Answer is group 1A. Why?

Answer 1

There is only one outermost electron.

Answer 2

So if the question asked which group forms only 2+ ions, the answer would be group 2 because it has 2 outermost electrons? And we know it has 2 outermost electrons based on the group number?

Answer 3

exactly right.