Pretty sure its called the 38th Parallel, or the Demilitarized Zone. :)
Ronald Reagan who was the 40th president and earned the title in his 8 years of serving as president
Answer:
I think that is China I am not sure
At this point, i think you can allow the line to miss a plot a little bit when passes between circles
pretty much it would look like this ,
just crosscheck it with the data if you're not sure
Hope this helps