Figure 18-4 This Figure Below Shows the Labor Market for Automobile Workers.The

Figure 18-4
This figure below shows the labor market for automobile workers.The curve labeled S is the labor supply curve,and the curves labeled D₁ and D₂ are the labor demand curves.On the horizontal axis,L represents the quantity of labor in the market.
-Refer to Figure 18-4.Which of the following events would most likely explain a shift of the labor-demand curve from D₂ back to D₁?

A) The price of automobiles decreased.
B) A large number of immigrants entered the automobile-worker market.
C) A technological advance increased the marginal product of automobile workers.
D) An increase in the demand for automobiles.