Question 26-28 refer to this following dialogue!

Ahmed: We had a great time at Drew's house Sunday, Why didn't you come?
Banu: I had to study for Spanish
Ahmed: If you had come with us, you would have seen an awesome movie.
Banu: Yeah? What?
Ahmed: We rented Back to the future. It's about a kid who time travels back to his parents high school days. He changes his own future. At the end, his parents...
Banu: Wait Don't tell me. If you tell me the ending, you will spoil it for me. I want to see it myself,
Ahmed: OK, But have you ever thought about that?
Banu: About what? A: About how things could be different. You grew up he in Baileyville, and you're almost an adult now. But what would your childhood have been like if you had different family?
Banu: Let's see. If I had had a different family, I wouldn't have grown up here in Baileyville.
Ahmed: And if you hadn't grown up here, I wouldn't have met you.
Banu: That's true. But getting back to the here-and-now, how did you do on the Spanish test?
Ahmed: I flunked. I wish I hadn't taken that course. I'm going to fail.
Banu: You just don't study enough. If you study more, you will pass this course easily this semester.
Ahmed: That's easy for you to say. You always get A's.
Banu:  Sometimes I don't. It's not automatic. I don't get A's unless I study hard.
Ahmed: I suppose you're right.
Banu: If I were you, I would try to do better on the next test.

What are they talking about?