The correct answer to this open question is "B line."
The labeled line that indicates the Great Wall of China is "B line."
The Great Wall of China is an icon of the most important ancient monuments in the world. In 1987, it was listed as a World Heritage by UNESCO. the wall has 13,170 miles and was built in a period of 2,500 years, and was designed to protect the Chinese territory from invaders. Astronauts say that the wall is so large and big that it can be seen from space.
