This is most likely specifically asking for World War I.
The first thing is rather not a gain, but a trust. Most of Europe, Asia, as well as the Middle East and Africa, were split into two camps. These camps were alliances, known as the Central Alliance (the German & Austrio-Hungary camp), and the Allies (The British & French camp).
The war was triggered by the assassination of Archduke Franz Ferdinand and his wife Sophie by a Serbian Nationalist who wanted to see a free Serbia. While Serbia was open to paying for reparation, Austrio-Hungary threw away the table in hopes of conquering and claiming Serbia for their own. The failure for the gears of war to stop before then was what caused the countries to go at war. Each country was bound by their alliance contract to help their members at need, and so it set off a chain reaction that ensued into a global war.
They had nothing to gain, but to keep their own honor, the survivability of their state, and the trust of their allies.
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Answer B boom towns
To start answers C and D make absolutley no sense so they are out of the pictrue leaving us with C and D
Oil wells dont have populations you cant live in or at an oil well however boom towns makes sense for the first characteristic.
You may think Boom Towns doesnt make sense for characteristics 1 and 2 however the phrase boom town was coined during Oklahoma's oil rush.
The awnser is B trust me
They lose outta business.
I think it is the first one
