The correct option is D
Plan Schlieffen is called to the plan proposed since the beginning of the 20th century by the chief of staff of the 2nd German Reich, Alfred Graf von Schlieffen, for the invasion and defeat of France, which was used at the time of the outbreak of the First War World. It consisted of Germany sacrificing East East Prussia to withdraw to the Lower Vistula, for the benefit of a powerful offensive front on the French border. The German Army would then mobilize 1 500 000 men for the attack in the west, while holding 500 000 in the east to repel the attack of the Russians, who totaled 2.7 million men. The French and British would mobilize about 3,901,000 men in the first weeks to repel the enemy.
The Barbarossa Operation (in German: Unternehmen Barbarossa), undertaken on June 22, 1941, was the code name given by Adolf Hitler to the invasion plan of the Soviet Union by the Axis Forces during the Second World War. This operation opened the Eastern Front, which became the theater of one of the largest operations of the war, scene of the biggest and most brutal battles of the conflict in Europe.
