The success of the Native American groups of the Northwest region was aided by the

A)Availability of wood for building houses

B)Development of advanced irrigation methods***

C)Rich supply of game animals, fish, and wild plants.

D)Use of sled dogs for transportation

3 answers

Well, I live in a fishing port so would not have checked B. If I lived in Arizona, well maybe.
Damon gave a BIG hint. Read and reread his post Then re-think.
Think about Washington and Oregon. Of course, it's C!