There are dozens of laptop manufacturers around the world.

According to the idea of efficient production,

a. government regulation will ensure that every firm produces at the lowest marginal cost.

b. a competitive market will drive most manufacturers out of business, leaving just a few firms to produce at the lowest possible cost.

c. there should only be one laptop manufacturer, making laptops at the lowest marginal cost.

d. each firm independently decides how many laptops to produce, and the marginal cost of the last unit produced will be the same for all firms.