What statement best summarizes Russia's experience on World War 1's Eastern Front?

Russia's experience on the Eastern Front during World War I was marked by significant military struggles and high casualties, largely due to inadequate supplies, poor leadership, and logistical challenges. Despite initial successes, the Russian army faced devastating defeats, such as at Tannenberg in 1914, leading to a loss of morale and widespread discontent among troops and civilians. These struggles contributed to the eventual collapse of the Russian Empire and the rise of revolutionary movements, culminating in the Bolshevik Revolution in 1917.