If a reader did not know that Ellery Queen is normally associated with the mystery genre, which sentence would first indicate that "Object Lesson, Part 1" is a mystery?

Why u delete my answer??

Explanation:

Third one

d) Miss Carpenter, walking home from a movie late the previous Monday night, had seen three boys dive out of a smashed bakery window and vanish into an alley.

Explanation:

This is the excerpt that would indicate that this story is a mystery. In this excerpt, we learn of how a person was witness to a crime. We learn that Miss Carpenter saw some boys leaving a bakery and vanish into an alley. They had clearly broken into the business, as the window was smashed. This happened late at night, which increases the mysterious mood of the event.