In a monopoly, what is the primary characteristic of the market structure?

In a monopoly, the primary characteristic of the market structure is that a single seller controls the entire market. This means there is only one producer or provider of a particular good or service, which allows the monopolist to set prices without competition. The absence of other sellers means that the monopolist can influence the market’s supply and demand dynamics, often leading to higher prices and reduced output compared to more competitive market structures.

In addition to control over price and quantity, a monopoly often results in less choice for consumers since there are no alternative products available. This market structure can deter entry by potential competitors due to significant barriers that protect the monopolist's position. These barriers could be legal permissions, resource control, or significant economies of scale that new entrants find difficult to overcome.

When comparing this to the other choices, the presence of many sellers would indicate a competitive market rather than a monopoly. Indistinguishable products usually refer to perfectly competitive markets where many firms offer identical goods. Finally, low barriers to entry are characteristic of more competitive markets, where new firms can easily enter the market and compete with existing businesses.