Final answer:
The characteristic that is NOT typical of the mystery genre is that the main characters and problems are revealed at the middle or end of the story. Usually, these are introduced at the beginning during the exposition and the mystery develops through rising action, climax, and falling action to a resolution.
Step-by-step explanation:
The characteristic that is NOT a typical feature of the mystery genre is:
A) The main characters and problems are revealed at the middle or end of the story. In the mystery genre, the main characters and problems are typically introduced early on, during the exposition phase of the story. This sets up the stage for what is to come and engages the reader's interest. The rising action then follows with the hero gathering clues and interviewing suspects, moving towards the climax, which is the peak of the action where the main conflict comes to a head. The end of the story often involves falling action and a resolution or continuation of the conflict where the mystery is usually solved.
The other options,
B) The plot includes a problem to be solved,
C) The hero of the story gathers clues and interviews suspects, and
D) The plot may involve an unexplainable event or a missing object or person, are indeed characteristics of the mystery genre. These elements contribute to the building of suspense and the structured progression through the plot. The hero works through the clues and suspects to solve the problem introduced at the beginning or to understand the unexplainable event or find the missing object or person.