Question: How many guest rooms are offered in the megaresort hotel and casino adjacent to CityCenter on the Las Vegas Strip?
Sentence (from "CityCenter"): As of 2015, the "CityCenter" branding has been largely retired, with the focus instead on the Aria brand of the development's centerpiece property in names such as the "Aria Express" (formerly "CityCenter Tram") and "Aria Art Collection" (formerly "CityCenter Art Collection").
Relevant evidence: No