Which of the following statement is incorrect?

A. The demand function specifies the relationship between quantity demanded and all the variables that determine demand

B. The demand curve is that part of the demand function, that expresses the relation between price charged for a product and the quantity demanded cetirus paribus

C. Elasticity can be measured in two different ways called point elasticity and arc elasticity

D. Arc elasticity measures the average elasticity at a point on the arc of the demand curve

Answer: Option D