Final answer:
Dwight D. Eisenhower contributed to World War II as a five-star general and Supreme Allied Commander, leading crucial military campaigns and the European Theater of Operations to Allied victory.
Step-by-step explanation:
Dwight D. Eisenhower's main contribution to World War II was his role as a five-star general and Supreme Allied Commander, which placed him at the forefront of planning and executing military operations leading to Allied victory in Europe. His exceptional organizational skills and strategic military mindset were pivotal in commanding the North African campaign and the European Theater of Operations. Eisenhower's leadership ensured the efficient mobilization and deployment of millions of troops, which was essential for securing war success against Axis powers.