What was the primary purpose of the city of refuge, as described in the Old Testament, and what does its existence reveal about the ancient Israelite legal system?

A To serve as a military stronghold against invading armies. B To provide a place of sanctuary for those who accidentally caused a death, protecting them from blood vengeance until a trial could be held. C To function as a center for religious pilgrimage and worship. D To act as a marketplace for trade and commerce between different tribes.