Diagrams A,B,and C Show 3 Individual Consumers' Demand Curves for Cement.Consumers

Multiple Choice

Diagrams A,B,and C show 3 individual consumers' demand curves for cement.Consumers A,B,and C constitute the entire monthly cement market in this region. FIGURE 6-3
-Refer to Figure 6-3.What is the market demand (in cubic metres per month) for cement at a price of $20 per cubic metre?

A) 0
B) 4000
C) 5000
D) 10 000
E) 14 000