The Tang Dynasty ruled over a strong and unified China because of which of these reasons?

The Tang Dynasty ruled over a strong and unified China because they had a strong army that could defend the borders and repel invaders.

Explanation:

The tang dynasty was successful in its time period or era. And it extended its clutch to the surroundings to spread its area and enlarge the Chinese dynasty. The tang dynasty made China a strong and unified one which had a very strong cooperation and boding among each other.

Tang dynasty formed a set or group of strong army that unified the whole China and defend the borders with enemy countries and repel the invaders. Enemy countries always try to find the weaker section of the opponent country so that they can easily go in. But tang dynasty protest it successfully.