The governor filed an _______ against the ruling of the tribunal.

In this sentence, the word "against" indicates that the governor is challenging or opposing the ruling of the tribunal. The word that would best fit in the blank is "appeal." An appeal is a legal request made by a party to a higher court to review and possibly overturn a decision made by a lower court or administrative agency. In this case, the governor is filing an appeal against the ruling of the tribunal, which means that they are asking a higher court to review the decision and potentially reverse or modify it. An injunction is a court order that requires a person or organization to stop doing something or to take a specific action. An objection is a formal expression of disapproval or opposition to something. An application is a formal request for something, such as a job or a permit. While these words are also used in legal contexts, they do not accurately describe the action that the governor is taking in this sentence.