What was one reason the battle of barbarossa became a turning point in the war?

The one reason that the Battle of Barbarossa became a turning point in the war was the number of casualties that the German army suffered. The Russians also suffered a huge number of casualties, but still they were able to hold their ground. The German army failed to push forward and ultimately they had to resort to attacking the United states.

Ithink it’s c , good luck on whatever : )