I think the answer is obviously letter D
Answer:
The building materials are influenced by local resources.
Explanation:
The farmers built structure based on the material obtainable in their area.Farmers having forest in their region built with wood obtained in that region,whereas those in the grassland used sod to build houses.

The Correct choice is C
<u>Demography</u> is the study of human populations and how they grow or decline.
Answer: The people migrated to other regions of Central Asia.
Explanation: To escape communism.