1.Draw a demand curve and label it D1. On the graph, illustrate an increase in demand and a decrease in demand, and label the curves D2 and D3, respectively. Starting on demand curve D1, explain the shift that would result from each of the following events:

a. an increase in income and the good is a normal good

b. an increase in income and the good is an inferior good

c. a decrease in the price of a substitute good

d. a decrease in the price of a complementary good