Ok, I'm kind of pissed about this one. I should have had it on the 3rd try. See spoiler to find out why I'm angry.
On my third try, I realized it was the Republic of the Congo, but the only choice in the list was the Democratic Republic of the Congo, which is a different nation. So I went with that, and was obviously wrong. When I got to my last guess, I had narrowed it down to where it had to be the Republic of the Congo, so I just typed it in, and it said unrecognized country. So I just typed "Congo," which is not its real name, and there it was. If I had known they had it listed under the wrong name, I would have gotten it on the 3rd try instead of 6th.