Refer to Figure 4-2. In diagram 1, the elasticity of demand for prices below $10 is a. infinity. b. greater than 1 . c. 0 . d. 1. e. less than 1 . With a downward-sloping straight-line demand curve, price elasticity of demand is a. decreasing continuously with price increases. b. indeterminate. c. rising continuously with price increases. d. constant everywhere on it. e. increasing to the midpoint of the curve and then decreasing