Final answer:
Tony's situation is an example of the free-rider problem, where he benefits from a union's efforts without being a member or contributing to it. Option d is the answer.
Step-by-step explanation:
Tony's situation, as an employee who benefits from the efforts of a union without joining or contributing to it, is characteristic of the free-rider problem. In such scenarios, collective action problems and free-riding often occur when union membership is not mandatory, yet benefits such as higher wages, collective bargaining rights, and better working conditions are enjoyed by all employees, irrespective of their union membership. As a result, individuals like Tony who choose not to join the union still reap the rewards of the union's efforts to secure better salaries, a retirement pension, and healthcare benefits without contributing to the cost of these efforts.