During the Last Glaciation, a Large Tongue of Glacial Ice

During the last glaciation, a large tongue of glacial ice occupied Lake Michigan for thousands of years.How, several thousand years after the retreat of the ice, an emergent coastline is developing along part of the lake.What geologic process is creating an emergent coastline in Lake Michigan?

A) Lake levels are falling.
B) Rebound of a depressed crust.
C) Subsidence of the land surface around the lake.
D) Accumulation of dunes on the beach.