Editorial: Our city's public transportation agency is facing a budget shortfall. The fastest growing part of the budget has been employee retirement benefits, which are exceptionally generous. Unless the budget shortfall is resolved, transportation service will be cut, and many transportation employees will lose their jobs. Thus, it would be in the employees' best interest for their union to accept cuts in retirement benefits.
Which of the following is an assumption the editorial's argument requires?
【选项】The transportation employees' union should not accept cuts in retirement benefits if doing so would not be in the employees' best interest.