Answer:
B. Qin
Step-by-step explanation:
The Qing Dynasty was the first unified and power-centralized state in Chinese history from 220 to 210 BC, after the Qin conquered all of the other Warring States. Even though the Qing Dinasty only 15 years, it held a significant role in Chinese history and enormously influenced the following dynasties. Thus, besides unifying China, his work combined the union of different state walls into a single Great Wall of China and an important new national road system.