Refer to the figure above. Moving from demand curve D1 to demand curve D2 could be caused by a(n):

Refer to the figure above. Moving from demand curve D1 to demand curve D2 could be caused by a(n):
A.increase in quantity supplied.
B.decrease in consumers’ incomes.
C.increase in the price of a close substitute.
D.increase in the price of a complement.
正确答案：increase in the price of a close substitute.