How do I connect the U-VERSE to HDMI 1 with ARC?

I have three HDMI connections in the back of my new TV, HMDI 1 has ARC in parentheses, HMDI 2 and HDMI 3 are both blank. Do I connect the U-VERSE to HDMI 1 with ARC in parentheses or either HDMI 2 or HDMI 3 which are both blank.