The industry that is a real-world example of an oligopoly from your list is commercial airlines.
In the commercial airline industry, a few large firms dominate the market, and they often make decisions based on the actions of their competitors, which is characteristic of an oligopolistic market structure. This contrasts with the other options, which are examples of different market structures: fast-food restaurants often operate in a monopolistic competition, pharmaceutical firms with patents operate in a monopoly, and agricultural vendors typically function in a competitive market.