The correct answer is the following.
The important decision made as a result of the alliances formed before World War 1 was that the six most powerful countries in Europe decided to split in two in order to protect themselves in case of war.
France, Britain, and Russia formed the Triple Entente. On the other side, Italy, Germany and the Austrian-Hungary formed the Triple Alliance in 1881. They pledge support in the case of a French aggression. The three nations would intervene immediately. France and Great Britain signed the “Entente Cordiale” in 1904, to help each other militarily, and they signed something similar with Russia in 1907.