Answer:
Step-by-step explanation:
A. Glaciers moved across the basin and melted.
The Great Lakes were formed by the process of glaciation. During the last ice age, which began about 2.6 million years ago and ended about 12,000 years ago, glaciers moved across the land, carving out basins and leaving behind depressions in the earth. As the glaciers retreated, they melted and filled these basins with water, creating the Great Lakes.