You have placed three transparent circles into your document. You wish to apply the transparency to the circles so that they do not interact with each other. How would you do this?
1) Select the circles, ensure Knockout Group is checked on the Effects panel and then change the Opacity
2) Select the circles and then change the Opacity in the Effects panel
3) Select the circles, group them and then change the Opacity in the Effects panel
4) Select the circles, change the Opacity in the Effects panel and then group the objects