Which statement best describes the effects of drought, desertification, and erosion on the people who live in the sahel on the edge of the sahara desert?
a) these factors have led to warfare between tribes in the region.
b) these factors have caused a great migration of people from the region.
c) these factors have caused the united nations to declare the region endangered.
d) these factors have led to hunger in the region because of a lack of arable land.

The correct answer is D.

Lenders give some money to borrowers in exchange for a retribution in the form of interest payments. In some cases, the interest charged is higher because the risk assumed by the lender with a certain borrower is very high. For example, in the case of countries' debt, debt from countries with larger risk of default has a large risk premium attached, which increases the interest that has to be repaid for that debt.

Another method to decrease the risk assumed is to provide secured credits, where the lender requires a collateral from the borrower, than the lender will keep in case of default in the repayments of the principal.