Which of the following is a correct statement describing a similarity between the tang and song dynasties? both dynasties were conquered in the north by invaders. both dynasties expanded their borders. both dynasties reduced the size of their military. both dynasties experienced economic prosperity.

- The Tang Dynasty relied heavily on a bureaucracy of merit, Tang rulers recruited government officials from the ranks of candidates who had progressed through the Confucian educational system and had mastered sophisticated curriculum concentrating on the classic works of chinese literature and philosophy. Most office holders won their posts because of intellectual ability. 
- Soon after developing a strong foundation for government, the dynasty began to show off their military. Tang forces expanded throughout northern vietnam, extended out to the Aral Sea, and went out all the way to Tibet. The Tang empire ranks as one of the largest throughout Chinese history
- The Tang Dynasty also enforced political theory: China was the middle kingdom and superior to all else, through this they developed the tributary system in which neighboring lands would make monthly payments towards china and supply them with gifts. They recognized chinese emperors as their overlords. In return the tributary states received conformation of their authority as well as lavish gifts. 
- Eventually the Tang empire collapsed due to peasant rebellions weakening their region. These peasant rebellions took place because of lazy leadership on behalf of the Tang rulers. 
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Andrei karlov was the russian ambassador