The best answer to the query is B. There are no substitutes.
In a monopoly, a single company or entity dominates the market for a particular good or service, and there are no close substitutes available for that product. This means that consumers who want the product must purchase it from the monopolist, as there are no alternative options that serve the same function or meet the same need as the monopolized product.
Here's how the other options relate to the concept of a monopoly:
Thus, option B accurately describes the scenario in a monopoly, where consumers have no alternative options, leading to no availability of substitutes.