Why was the D-Day invasion crucial for the Allies’ Europe First strategy?

The D-Day invasion opened a major Western Front, forcing Germany to fight Allied armies in the west as well as the Soviet Union in the east. As the Allies advanced from France, German forces were pushed back eastward, helping the Allies defeat Germany in Europe. The invasion did not immediately force Germany to surrender, so choice C is incorrect.

AI-written and checked against the verified answer.