Answer:
Early humans migrated to America crossing the Bering Strait, which back then was a wide swath of land, about 15,000 years ago.
B is the best answer to the question
The Great Wall of China, built more than 2,000 years ago, stands as one of the monumental feats of ancient engineering. But before the Great Wall, warring Chinese dynasties built many other walls for protection. There are 7,000 watchtowers, blockhouses for soldiers, and beacons to send smoke signals. Nineteen walls have been built that were called the Great Wall of China. The first was built in the 7th century BC.
Olmec civilization was the society that lived along the west coast
