The correct combination of the alternatives is:
4. a, c, and d
Explanation:
a) Desertification can indeed lead to increased competition for scarce resources and conflicts.
c) It can result in food shortages due to a lack of arable land and water.
d) Desertification often causes reduced crop yields as the quality of land declines.
b) The statement that more than 90 percent of the desert area has been reforested is incorrect; desertification is


