Answer:
The correct answer is option B. "The Western Front was a defensive stalemate from 1914-1918 while the Eastern Front was much more fluid".
Step-by-step explanation:
During World War I, the Western Front was a defensive stalemate from 1914-1918, making little progress and remaining static after German's army was defeated in its Schlieffen Plan. On the other hand Eastern Front was much more fluid in this period of the War, knowing the beginning of this period as "The War of Movement" for this front.