The correct answer would be The Ottoman Empire
"Austria-Hungary<span> declared war on </span>Serbia<span> after serbian nationalists assassinated Archduke Franz Ferdinand and his wife, this was not necessary as only a few serbians participated and these assassinations usually did not result in war" (prezi.com)</span>
Answer: The war officially ended with the February 2, 1848, signing in Mexico of the Treaty of Guadalupe Hidalgo. Mexico gave up all claims to Texas and recognized the Rio Grande as America's southern boundary.
Explanation: Hope this helped!! :D