While the western Roman Empire collapsed, The Byzantine(eastern Roman) Empire was able to survive because A.) it was the center of the Roman Catholic Church.
B.) it did not have a diverse , multi-ethic population.
C.) it had a trained bureaucracy and an experienced and loyal army.
D.) it was able to conquer the Germanic and Gothic tribe in the west.

C.) it had a trained bureaucracy and an experienced and loyal army.

Explanation:

d: social contract theory

the right answer is the third one: turnpikes went short distances to connect markets. turnpikes, also known as toll roads, were very important for trade and transportation (of people, goods and products) in the 19th century, coinciding with the expansion towards the west. they contributed significantly to the economic development of the united states.