Which dynasty ruled from 618-907, during which time they expanded china farther west, influenced korea and other regions, and maintained contact with japan ?

The Tang Dynasty

Explanation:

The Tang Dynasty ruled between 618-907. This dynasty was able to gather professional armies and conscripts of hundreds of thousands of soldiers to confront the nomadic powers in the field of Central Asia and the lucrative commercial routes along the Silk Road. Several kingdoms and states paid tribute to the Tang court, and the Tang also conquered or subjugated several regions that it indirectly controlled through a protective system. In addition to political hegemony, the Tang expanded China further west and also exerted a powerful cultural influence on neighboring states, such as those of Korea, Japan and Vietnam.

b. native americans them

no one really purchased it themselves, it was all america, they had debates etc.