This one here I messed up on a little bit. There were two possible answers, C and G. C is the more "simple" of the two, although G would technically still work.
As you can see above when the dots are inside the circle they count as (+1) and when they are outside the circle they count as (-1). The column on the left is always added to the middle column to produce the column on the right. In this respect the equation to solve this puzzle is (2-3) or (-1). This is represented as a dot outside the circle, or as some posters pointed out a circle inside and two outside.
Great job and the scoreboard on the right has been updated!