Product development is efficient if the marginal social benefit from an improved product$\_\_\_\_\_\_\_.$

Product development is inefficient because in monopolistic$$ competition, $\_\_\_\_\_\_\_.$

A$.$

equals its marginal social$$ cost;

profit is maximized when marginal revenue equals marginal$$ cost$,$ and marginal revenue is less than price

B$.$

is greater than or equal to its marginal social$$ cost;

firms receive a greater return from advertising than from product development

C$.$

increases the price that a firm can$$ charge;

profit is maximized when marginal revenue equals marginal$$ cost$,$ and marginal revenue is less than price

D$.$

equals its marginal social$$ cost;

product development raises the price the firm can$$ charge, which decreases the quantity sold