Year 1898, so the 19th century
The countries not included in the original alliance system were pulled into the war because they had alliances with the countries within the original alliance system. That they promised to be on their side should there ever be a war. However, this caused many conflicts because some countries had alliances with both sides.
Hope this helps.
The answer is C) to inflict so much damage that Georgians would call for an end to the war.