Hastorf and Johannessen Argue That Changes in the Types of Fuel

Hastorf and Johannessen argue that changes in the types of fuel used through time in the Upper Mantaro area of Peru are best explained by:

A) changes in the abundance of high quality versus low quality fuel caused by environmental change.
B) increasing population density that denuded the landscape of trees, forcing people to rely more and more on low quality fuel through time.
C) forced fuel management programs mandated by an elite social class.
D) a combination of materialistic and ideological explanations.