The correct answer is - A) the Berlin Wall.
The relic boundaries are one of the multiple types of boundaries around the world. This type of boundary is a boundary that no longer exists, it existed in the past, it was separating two parts artificially, but it is no longer there.
A perfect example of this type of boundary is the Berlin Wall. The city of Berlin was divided into two parts, and it was a boundary set by the countries that invaded Germany after World War II, thus separating the country into two countries, East Germany and West Germany, which was also a separation because of political influence. The Berlin Wall though, was taken down, and with that move the boundary was removed, and the country and people reunited.
