In a Dry, Fault-Originated, Basin and Range Area Like the Okanagan

In a dry, fault-originated, basin and range area like the Okanagan Valley of BC and Washington, which environmental conditions are associated with steep mountain slopes and ephemeral streams?

A) Faulting is probably still active in the mountain rain shadow, producing a semi-arid climate.
B) Faulting ceased millions of years ago, resulting in an arid desert.
C) Faulting is probably still active, resulting in a steppe area with a rainy season.
D) Faulting ceased millions of years ago, resulting in moderate rainfall but very hot climate.