East-West Trade Throughout Afroeurasia Was Achieved Through Which of the Following

East-west trade throughout Afroeurasia was achieved through which of the following?

A) systems of relay in which merchants remained in a relatively fixed territory and sold their goods to other merchants in neighboring regions
B) a system in which groups of nomadic merchants traveled great distances to sell their goods
C) a system in which many soldiers also engaged in trade, as they were some of the most well-traveled members of society
D) a system in which rulers appointed trusted merchants to carry luxury goods and obtain large profits for the royal court