he demand equation noted in In-text Exercise 2.2 is Q = 20 – 2P. Which of the following statements is true?
A) If we use the following graph to illustrate the demand curve, then the slope of this demand curve is ΔP/ΔQ -1/2.
B) In the demand equation (Q = 20 – 2P), ΔQ/ΔP = -1/2.
C) If we use the following graph to illustrate the demand curve, then the slope of this demand curve is ΔQ/ΔP = -2
D) None of the above