The house is made of sod. Sod is a thick piece of dirt with grass and roots attached. Which of these is one of the main reasons that some pioneers built sod houses?
A. In some areas, there were few trees to use for building.
B. They thought sod houses were stronger and would last longer.
C. They could not afford an axe to cut down trees.
D. They thought sod houses were more beautiful than wooden ones.