For What Reason Did the German High Command Redeploy 100,000

For what reason did the German High Command redeploy 100,000 troops,undermining the success of the Schlieffen Plan?

A) to respond to Russia's invasion of East Prussia
B) to deflect the United States' entry into the war
C) to prevent French troops from advancing into Italy
D) to calm the growing concerns of citizens in Austria
E) to receive training in modern mechanized warfare