Answer:
C
Explanation:
in bartering it's hard to distinguish a common measure of value, for example one mans trash is another mans treasure, but thanks to money having a set worth in all country's, it makes it a more viable option.
Answer: Invasions by Barbarian tribes
The most straightforward theory for Western Rome's collapse pins the fall on a string of military losses sustained against outside forces. Rome had tangled with Germanic tribes for centuries, but by the 300s “barbarian” groups like the Goths had encroached beyond the Empire's borders.
Japan controlled the Korea peninsula as it was the first thing they took as an attack on China.
That evolution takes place by the principle Natural Selection Basically the strongest survive and reproduce
I need to know the context of the situation. if this is now then its completely different from say the 1870's or late 19th century