What is the goal of city planning?
a. to return to agrarian ways of life
b. to address urban problems
c. to encourage localities to combine
d. to prevent people from migrating to other countries

The goal of city planning is to "address urban problems". The city needs to be planned correctly so that everything can run smoothly and without problems. It also refers to architecture, transportation, zones, etc. 

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.