Final answer:
A tragedy is the type of story that most commonly concludes with an unhappy ending, characterized by serious tone and the downfall of a protagonist.
Step-by-step explanation:
Of the given options, tragedy is the story template that usually concludes with an unhappy ending. The defining characteristic of a tragedy is its serious tone and the intense emotional journey it takes the audience on, often concluding with death or a series of unfortunate events that lead to the downfall of the protagonist. By contrast, comedies generally end happily, often with events like a marriage, and are designed to make the audience laugh rather than feel the deep emotional impact associated with tragedies. The third option, rebirth, typically involves a transformation or renewal and doesn't necessarily end unhappily.
Tragicomedies, on the other hand, blend elements of both tragedies and comedies and often conclude with a positive resolution despite serious themes and the heightened emotional experiences they may invoke.