If a firm sells 10 units of output at $100 per unit and 11 units of output when price is reduced to $99, its marginal revenue for the last unit sold is

In monopolistic competition, an increase in a firm's advertising

A) has no effect on its average cost curves. B) has no effect on demand. C) increases the firm's average total cost. D) increases the firm's marginal cost.

If the absolute price elasticity of demand for automobiles is equal to 0.75, we say

A) that demand is inelastic. B) that demand is elastic. C) that there is a strong responsiveness of quantity demanded to automobiles price cuts. D) none of the above is correct.