The properties of permafrost cause:
Water to seep rapidly into the soil
Water to create sinkholes in the limestone below
Water to collect on the surface
Water to return to the surface as steam

The Porcupine caribou calving grounds are:
The foothills of the Ogilvie Mountains
The valleys along the Richardson Mountains
The open meadowlands of Alaska
The northern coastal plains

The predecessors of the Vuntut Gwitchin:
Hunted Pleistocene species on the steppe tundra
Were the ancestors of all North and South American aboriginal people
Both a) and b)
Neither a) nor b)