Answer:
ii
Step-by-step explanation:
While electron affinity increases as you go up and to the right across the periodic table, electron affinity is most likely positive when there is a fully filled subshell.
In 1, the last subshell is 3s1, which isn't filled.
In 3, the last subshell is 3p1, which isn't filled.
In 4, the last subshell is 3p4, which isn't filled.
And in 5, the last subshell is 3p5, which isn't filled either.
However, in 2, the last subshell, 3s2, is completely filled. Therefore, it is most likely to have a positive electron affinity.