Assyrian power and wealth were a result of: the b00ty from war and the trading empire they developed (it will not let you use b00ty with os)
the use of iron in tools and weaponry
the development of politically rich city-states

The b00ty from war and the trading empire they developed

Explanation:

The Assyrians had a lot of power and wealth because they were very capable of warfare. They had advanced war tactics and their doctrine and technology were pretty new to their enemies. They focused on conquering a whole empire and persisted in that goal to the end. They were not only a military force but had developed arts and medicine as well as education that all helped the empire greatly.

i would go with the last one

the anwser is a) to prevent military conflict