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.
This is just a helpful reminder because i haven’t read the book yet but here’s how you can tell what perspective (POV) it is:
(1st perspective uses:
We, us, our,and ourselves are all first-person pronouns. Specifically, they are plural first-person pronouns. Singular first-person pronouns include I, me, my, mine and myself.)
&
(2nd perspective uses:
you (singular and plural personal pronoun)
yours (singular and plural possessive pronoun)
yourself and yourselves (singular and plural reflexive/intensive pronouns))
&
(3rd perspective uses:
he, him, his, himself, she, her, hers, herself, it, its, itself, they, them, their, theirs, and themselves)
It was actually among four countries; Austria-Hungary, Germany, Ottoman Empire (Turkey), and Bulgaria started as an alliance. Germany lead the Central Power group.
Among the three countries, Germany had the greatest military advantage. It is also the militarist war designer and strategist that led their alliance.
Austria- Hungary unification and involvement during World War I started after the assassination of their King Archduke Ferdinand. Austria and Hungary believed that it was a Serbia assassination plot.
The Ottoman Empire signed the alliance with Germany because of its good economic relationship.
Bulgaria who came in last in the Alliance. It claimed that Serbia took a part of its land that made it get to war.
(got this from another question but I hope it helped)
I think the answer is the United States