Which of the following sentences is an example of the passive voice?

The sentence "Mario was given $25 after he won the contest" exemplifies the passive voice because the subject, Mario, receives the action rather than performing it. In this construction, the focus is on what happens to Mario; he is the recipient of the action (being given money), rather than being the one who is actively giving or paying. This structure is characterized by the use of a form of "to be" (in this case, "was") combined with the past participle of the verb ("given"). This highlights the action as it relates to the subject, shifting the emphasis from the doer of the action to the receiver.

In contrast, the other sentences illustrate active voice, where the subject is clearly performing the action—such as needing to pay, giving, or having paid—demonstrating agency and direct involvement in the depicted events.