The answer is 4/5 because I just got it do it 4/5
Hey man!
The discovery of large oil reserves, this is the principal actor that changed the modern countries in the arabian peninsula. One of this examples was the Iraqi War when Saddam Hussein invaded Kuwait.
Deindustrialisation which resulted in less factories as companies shifted their manufacturing operations to countries of lower production cost. This results in less pollution to the environment as the industrial scene is replaced by the growing services sector. The increasing emphasis on human development and henceforth the sustainability of development is also a contributing factor.
I think the answer is B or C. It was limited but I'm not sure that it completely closed. Hope this helps.