Answer:
1. The Battle of Verdun in 1916 was the longest single battle of World War One. The casualties from Verdun and the impact the battle had on the French Army was a primary reason for the British starting the Battle of the Somme in July 1916 in an effort to take German pressure off of the French at Verdun.
2. Ultimately, the French resistance at Verdun proved a turning point, halting the German advance. The heavy German losses at Verdun combined with even greater casualties suffered on the Somme also created a manpower crisis within the German army that would become increasingly difficult to resolve as the war progressed. A different outcome would have provided the opposite.
3. The fortress of Verdun with its surrounding fortifications along the Meuse River was selected because it threatened the main German communication lines, it represented a salient in the French defenses, and the loss of such a storied citadel would be an enormous blow to French morale.
Step-by-step explanation: