The correct answer is D: housing and artifacts.
There is no written evidence of the Anasazi or Ancestral Pueblo existence, so scientists have to <em>rely on archeology</em> to study their existence, economy, religion and culture.
It is considered that some of their descendents are the Zuñi and the Hopi, but there is no actual evidence of their kinship. The Ansazi civilization dissapeared before the arrival of the first Europeans and the reason they left their homes is unknown.
Many <em>objects were preserved</em> thanks to the dry weather on the region, allowing archeologists a better understanding of their life. Some <em>squeletons</em> were also found, this has provided knowledge of their health, nutrition and morphology.