A firm has a demand curve given by p = 200 - 5Q. When we graph the demand curve with price on the vertical axis, what information does the slope provide?
a. If we lower price by 5 units then we will sell 1 more unit.
b. If we lower price by 1 unit then we will sell 5 more units.
c. If we lower price by 1 unit then we will sell 5 fewer units.
d. If we lower price by 5 units then we will sell 1 less unit.