Which of these is a natural monopoly?
cell phone service computer repair package delivery service sewage treatment

A natural monopoly is a monopoly in an industry in which high infrastructural costs and other barriers to entry relative to the size of the market give the largest supplier in an industry, often the first supplier in a market, an overwhelming advantage over potential competitors. This frequently occurs in industries where capital costs predominate, creating economies of scale that are large in relation to the size of the market; examples include public utilities such as water services and electricity.[1] Natural monopolies were discussed as a potential source of market failure by John Stuart Mill, who advocated government regulation to make them serve the public good.

DefinitionEdit

Two different types of cost are important in microeconomics: marginal cost, and fixed cost. The marginal cost is the cost to the company of serving one more customer. In an industry where a natural monopoly does not exist, the vast majority of industries, the marginal cost decreases with economies of scale, then increases as the company has growing pains (overworking its employees, bureaucracy, inefficiencies, etc.). Along with this, the average cost of its products decreases and increases. A natural monopoly has a very different cost structure. A natural monopoly has a high fixed cost for a product that does not depend on output, but its marginal cost of producing one more good is roughly constant, and small.so it is a sewage treatment

Your answer is d.all of the above! hope this ! : )