What made the qin dynasty significant

Inaugurated the political system that lasted until 1912.

Build walls that eventually developed as the Great Wall of China.

Explanation:

The Qin Dynasty governed China from 221 BC to 206 BC, being the first dynasty of Imperial China. While it was the shortest dynasty of Imperial China, it inaugurated the system that lasted until 1912. They also build connecting walls around the northern border, which eventually developed into the Great Wall of China.

the answer is fifth.