The appearance of Tybalt foreshadows Romeo's eventual death as he narrowly escapes it at Tybalt's hands. It creates a sense of impending danger for Benvolio, Mercutio and the audience as it is the first indication that Romeo is doomed.
The phrase <em>with exciting plots </em>is used as D. adjective phrase, because it modifies the noun <em>books.
</em>What kind of books? - (The ones) with exciting plots. <em>
</em>
Answer: A. Elenita versus the music of her parents' homeland.
Explanation: in literature, a conflict is a struggle between opposite forces, usually between a character (the main character or a very important one) and himself (internal conflict), society or another character (external conflict). In the given excerpt from Gravity by Judith Ortiz Cofer we can see an example of an external conflict between a character (Elenita) and the music of her parents' homeland, which her mother used to listen to in the evenings.