Answer:
D. simile.
Explanation:
In Marie Devers' "The Junior Detective", the speaker narrates how she came upon the profession of being a detective. And in her description, she mentions how she stumbled upon "this vocation", that is, being a detective.
The figurative language that is used in these lines is a simile where the speaker becoming a detective is compared to the process of how detectives solve crimes, "stumbling" upon evidences and declaring a "verdict" at the end of the investigation. Similes are used to compare one thing with a completely different kind, which provides a more detailed image of the thing talked about. And in these lines, her description of how she became a detective is vividly described, allowing the readers to have a proper understanding of the process.