How did the sinking of thelouisiana 1915 affect world war i

During 1915, a German submarine sunk the ship the Lusitania. This passenger ship had both British and American citizens on it. Ultimately, the attacking of this ship outraged European and American citizens alike. This is due to the fact that hundreds of innocent civilians were killed. This is why German began restricting its submarine warfare, as they did not want to further anger other countries during this time of war.

Ibelieve the answer is answer 5