Which sentence uses passive voice?

Mark's torn pants and sweatshirt made his mother sigh.

The snow from last week's storm melted when temperatures rose.

The long-awaited victory was earned by every player on the team.

Before she left for the airport, Mrs. Kelly kissed her cat and dog.

Among the choices indicated above, the sentence which is constructed in passive voice is:

The long-awaited victory was earned by every player on the team.

There are two voices of a sentence. In the passive voice, the noun or noun phrase is used as a subject of the sentence whereas in active voice it is used as the object of the sentence.