Actually the studying the Egyptian civilization is mandatory if you wish to study the ancient history and its civilizations. The Egyptian civilization is considered as one of the very first that was built on the principle of unity as a whole state or entity, and it kept on spreading that at times, it reached from the Levantine to the North-West of Africa. The Mesopotamian civilizations, the Helenstic civilization, the Babylonian civilization and the Phoenician civilization were affected by the Egyptian civilization in one way or another.
Besides, The study of the Egyptian civilization is an interesting topic since it reached a level of development that was hard to reach at that age (the pyramids for example). Many sciences thrived and were practised in ancient Egypt. There's even some secrets that have been uncovered so far, despite all the technological advance we have reached, such as the secret chemicals that were used in the mummification and preserving the dead.
B. Christianity because they were moving to be free
In the period of the Sui Dynasty (581-618 AD), Chang’an before was named Daxing. However, in a later time, the city got new reformations and innovations and was renamed Chang’an by the Tang dynasty administrators which then served as the Tang capital until its collapse in 904 AD.
This ancient imperial capital was the eastern commencement point of the Silk Road. The Silk Road has been of an enormous importance to the trade and cultural exchange to Xi’an (formerly Chang’an) as well as important crossroads for people from entire China, middle east, Rome, and Central Asia. The city thus developed into a hub of diverse ethnic recognition and religious beliefs.
In addition to the above, the tang dynasty manifested a tremendous cultural and religious fluorescence when it grew into a Buddhist learning center and also Taoism, attracting many pilgrims, and other scholars as well as philosophers. This didn’t end only with Buddhism, many other faith denominations emerged such as Nestorian Christianity, Zoroastrianism and Manichaeism, and later Islam.
therefore, the factors that made the tang cipital of Chang'an a center of culture and trade were mainly A and C; It welcomed foreigners and their beliefs, it was located at one end of the silk Road.
