The correct answer is option 1, Dreikaiserbund Treaty. The "Three Emperors` League" was formed in 1873 and was also referred to as the Dreikaiserbund Treaty. It was an alliance between Germany, Austria-Hungary, and Russia. The purpose of the treaty was to maintain peace among the three countries and to protect their common interests in Europe. However, the alliance started to weaken over time due to conflicting interests and tensions between the member nations. The Dreikaiserbund Treaty eventually fell apart in 1887 when Russia and Austria-Hungary had disagreements over territorial disputes in the Balkans. This breakdown of the alliance contributed to the growing tensions and rivalries in Europe, leading to the formation of new alliances such as the Triple Alliance and the Dual Alliance.