Which of the following is NOT a characteristic of a monopoly?

In a monopoly, a key characteristic is that there is a single seller who controls the entire supply of a product or service within a certain market. This means that the monopolist can influence the price and availability of their product without competition. There are also high barriers to entry in a monopolistic market, which prevent other businesses from entering and competing with the monopolist, thus maintaining their market dominance.

Another characteristic of a monopoly is that it acts as a price maker rather than a price taker, meaning it can set prices above the marginal cost to maximize profits, particularly due to the lack of competition.

While a monopoly may offer a product that serves a specific need, it does not necessitate that the product is identical across the market. In fact, since there are no competitors, the monopolistic product is often differentiated in terms of branding, quality, or price. Therefore, the presence of identical products is not a requirement or characteristic of a monopoly, making it the correct answer in this context.