The correct answer is A) D-Day.
The D-Day Invasion was one of the major turning points of World War II. In this invasion, the Allied Powers invaded off the coast of Normandy France. This was the largest amphibious invasion in military history and resulted in hundreds of thousands of casualties between the Allied and Axis powers. This was one of the most important battles of WWII, as the Allied victory would lead to the freeing of Europe from Nazi control.