Answer: B exposition
Explanation: To answer this, you can use process of emlimination. This excerpt doesn’t hint that a person is thinking back on this event, or telling it. It seems like they are living it. You know it can’t be dialogue because no one is talking back and forth. Unless this excerpt is a memory, it cannot be backstory. It could possibly be exposition, because exposition is a memory with a narrator. I don’t see it being plot because unless this is the crux of the story, the answer is out of contex and doesn’t apply.