Answer:
I think its g. belief in one God. btw, Jesus Loves you. John 3:16 For God so loved the world that he gave his one and only Son that whoever believes in him shall not perish but have eternal life. have a Blessed day
Based on the map I've attached, I'd say that Christianity spread to
most of the Roman Empire by 476 AD. If you look at the map, you will see that before 325, there were some places in Spain and Italy mostly where Christianity existed, however, after that year, it only continued spreading throughout Europe, which mostly belonged to the Roman Empire at the time.
Economic productivity has declined in some countries as a result of : Bubonic Plaque
In the past, Bubonic plaque manage to kill about 25 - 30 % of the world population, these greatly decrease the number of workers that could contribute to production activity and reduce Overall economic productivity in several countries