The correct answer is - Large numbers of migratory birds;
The number of the migratory birds has always been pretty high and it hadn't resulted in the drying up of the Ogallala Aquifer, not to mention that those birds can not even reach that water because it is underground. Also, the number of the migratory birds have been steadily lowering, so even if they were using that water for drinking, it wouldn't have caused the drying out.
The Ogallala Aquifer has started to dry out because of numerous reasons, with the usage of its water for irrigation being the prime reason. The droughts have become longer, and the temperatures little higher, while the rainfall slightly smaller, so all of that affected the reserves of water in the aquifer negatively.
C. Controlling trade between Asia and Europe
D. They led small, surprise attacks on British troops.
Germany was extremely divided in the period since it was not yet a unified country. This lack of centralism led to rampant corruption that always ended with church as a unified body having huge power over the separated individual regions. This allowed extreme corruption to prosper and the church was basically exploiting people. Martin Luther was sick of this and he used the newly developed idea of a printing press to spread his message in order to fight the Catholic church's corruption.
There are several ways in which the government took action to distract and control the masses of Rome, but perhaps the greatest way was by forcing all the men into military service.
