Hey!! I don’t really know but I believe the answer is 4.
Answer:
this question needs more support in order to be answered.
Explanation:
Probably because of Louis XIV.
The alliance system in Europe basically was if one country went to war, all of the other countries in that alliance would back up their buddy and go to war as well. This is what happened when Archduke Franz Ferdinand was assassinated and Austria-Hungary was arguing with Bosnia and each of their alliances go pulled in with them too.