The right option is; A. the removal of mass from the crust causes the crust to rise.
Isostatic rebound occurs when the removal of mass from the crust causes the crust to rise.
Isostatic rebound is the uplift and readjustment of land masses that were depressed by the large weight of ice sheets during the last ice age which had caused isostatic depression. Due to the relative elasticity of the mantle, the land was able to rebound upwards when the ice has melted. Isostatic rebound occurs in landforms such as relict cliffs and raised beaches.
