Answer:
Analyze fraternal polyandry in Himalayan south-central Asia with respect to material conditions.
Since the population of the region is high and there is no farmable land therefore they want to keep it as one unit and practice fraternal polyandry in a way that a woman will be married to many brothers and therefore they wont have to fragment the land. They have to keep the population of their family low and this system works for them.
What specific problems are posed by what specific material conditions, and how are they solved?
Major condition of material is land and they dont want to split it between the brothers. If they all will have a separate wife, there are chances of fighting and asking for their fragment of the land. Therefore fraternal polyandry works for them
Is this a simple causal relationship?
No it is not. It is more like of an organization / corporation relationship where land must be retained as a collective unit.