Which best describes the significance of the Great Wall in the history china

Which best describes the significance of the Great Wall in the history china?

Emperor Qin Shihuang's contribution to the design of the Wall is considered to be of great importance as it ensured peace for the people in the northern part of China against the Huns and established a pattern of defense for future generations. The Great Wall of the Qin Dynasty was built at the expense of many lives.