The answer to the question above is "B. less available tax revenue" based on the GDP calculation formula. The GDP calculation formula is stated as GDP = C + I + G + (Ex - Im) where C is consumers spending, i is investments, G is government spending, and (Ex - Im) is the difference between export and import. A low GDP means a low spending has occurred in the country which results in a decrease in tax revenue.
The geological terrain of this region is primarily steppe, grasslands which have poor soil for agrarian (agricultural) lifestyles. Historically, steppe people have had to rob agricultural societies (i.e. Mongols in China) or just eat meat they hunt.