Pioneer farmers settling the grasslands of the american west often build houses of sod, while early settlers of the eastern forest built wooden structures like log cabins. this suggests that building
a) are chosen becasue of the diffusion of popular culture.
b) are strongly influenced by local resources
c) are a uniform feature of folk culture
d) are commonly imported long distance because of local folk culture
e) all of the above

b. local resources

Explanation:

The most important reason behind the building materials used to construct houses in different geographical areas of the early United States was the ready availability of resources. Settlers lack the physical or financial means to transport building materials over long distances and so used what resources they could find close the area that they settled. The importance of log cabins and other dwellings in popular culture only became important in later years as movies, books, and the popular imagination associated certain types of structures with specific geographical areas.

a characteristic is a deep cut in the earth or left over rock aka till.  

a. themes: sub fields