How were the Okanogan Highlands formed?

(1 point)
Responses

by subduction, which caused huge folds in Earth’s surface
by subduction, which caused huge folds in Earth’s surface

as a result of retreating glaciers carving great valleys into the earth
as a result of retreating glaciers carving great valleys into the earth

when molten rock from under the earth approached the surface
when molten rock from under the earth approached the surface

when the collision of volcanic island chains and ocean rocks formed new earth
when the collision of volcanic island chains and ocean rocks formed new earth

The correct answer is: as a result of retreating glaciers carving great valleys into the earth.