The market demand curve for a perfectly competitive industry can be downsloping while the demand curves for each of the firms in that perfectly competitive industry are horizontal. this is because?
a. a competitive firm only realizes a change in the price when market demand shifts.
b. the market demand depends on the number of firms in the market.
c. the supply of the product can be upsloping, so the demand for the product is downsloping
d. a competitive firm's output decisions do not impact the market price since its output is such a small faction of its industry's total output.