The correct answer is:
Allied: the United Kingdom; Central Powers: Germany.
The Allies had a lot more potential wealth to be spent on WW1. It has been estimated that the Allies spent $147 billion on the war while the Central Powers invested only $61 billion. Britain and its Empire on the Allies side spent $47 billion while Germany spent $45 billion.
The Sahel was the last area in the northern parts of Africa, where vegetation can survive and where people were living at the time. Following the Sahel to the North one can find the Sahara desert which is a natural barrier that no invading force could trespass.
The treaty of versailles declared Germany guilty of aggression.
Germany was forced to pay 33 billion dollars and many parts of it like Alsace lorraine, coal mine at Saar were given to France.
Moreover it had to supply huge amounts of coal to Belgium and Italy as well.
Its army,navy and ships were reduced.
In short, it had to take over the blame and responsibility of the World War1
