The Figure Above Shows Lorenz Curves for a Nation

The figure above shows Lorenz curves for a nation.
-Based on the figure above,which of the following can cause a movement from point C to point D on the Lorenz curve for income?

A) an increase in income for the bottom 60 percent of households
B) an increase in income for the bottom 80 percent of households
C) a decrease in income for the bottom 60 percent of households
D) a decrease in income for the bottom 80 percent of households
E) None of the above answers is correct.