Task: Question Generation
Input (English): New York has architecturally noteworthy buildings in a wide range of styles and from distinct time periods, from the saltbox style Pieter Claesen Wyckoff House in Brooklyn, the oldest section of which dates to 1656, to the modern One World Trade Center, the skyscraper at Ground Zero in Lower Manhattan and currently the most expensive new office tower in the world.
Output (English): The most expensive office tower built in the world today is what?