(A) builds a bridge from the premises to the conclusion. We know from the premises that the city will charge a fair price, and that the requirement will benefit all city residents. (A), then, allows us to conclude that the city has the right to require homeowners to connect to city water services.

(B) is close to a reverse of what would strengthen the argument. It tells us what’s necessary (”only if”) in order for it to be appropriate for the city to require homeowners to connect to water services. But that will never allow us to prove that the city should require homeowners to connect to the service. (”A only if B” can NEVER prove that A is true.) Also, the issue is whether the city has the RIGHT to require the connection, not whether it should require the connection.

(C) tells us when the city does NOT have the right to do something. But we want to prove that the city DOES have the right to do something. (If you think this answer strengthens you’re confusing sufficient and necessary conditions.)

(D) concerns whether residents have the right to complain about something. But the argument concerns whether the city has the right to do something. Whether residents have the right to complain is a separate, irrelevant issue.

(E) doesn’t establish when a city has the right to do something. It tells us the implementing a certain requirement is necessary to increase revenue and becoming a healthier/safer place to live. But it doesn’t tell us that the city has the right to do something.