This is a federal order requiring states to provide a service.
a. preemption
c. restraint
b. grant
d. mandate

speed

explanation:

answer; earthquake;

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.