The antecedent of the pronoun “it” is Chicago (answer A). The reader can easily recognize the antecedent of a pronoun by replacing it in the sentence, and he or she can determine if the meaning of the sentence has sense or not.
Example: The class members chose Chicago to visit because Chicago provides the best opportunity for education and entertainment.
The answer would be the “main idea” or “theme”.
Romeo speaks these words shortly after being banished.
He is upset because now he cannot be near Juliet. Carrion flies may touch her, but he cannot get near her. As a result, carrion flies can woo Juliet better than he can, since he cannot get as close to her as he can.
Carrion flies are not banished and can therefore get close to Juliet, that is why Romeo says he is less honored than the flies.
I think A. Because at the end it says “Think seriously about choosing a pet” and it states reasons.