Why did early Chinese civilizations and dynasties thrive for thousands of years with little outside influence?

A.
The Great Wall prevented invasions.

B.
The Chinese did not need to trade for goods and resources.

C.
Mountains and deserts provided natural barriers.

D.
China is protected by water on all sides.

ms . sue, just answer the question

i still need helpppp!!!!!!

The answer is A?

really why i need to know if it is A, B, C, D

hello what is the answer trying to figure it out im really confused

I have no clue what i'm doing T-T

omg just plz answer

wow alr I'll answer as fast as I can

bro isn't really fast at answering because its been EIGHT MONTHS

you freaking idiots JUST ANSWER THE DAMN QUESTION YOU FRICKING MORONS