Question: Which London bridge is nearest to the Westminster Millennium Pier and Big Ben?

Context paragraphs:
London Bridge City Pier: London Bridge City Pier (also known as London Bridge Pier and City Pier) is situated on the south bank of the River Thames in London, UK, close to London Bridge.  It serves as the main pier for the City of London and City Hall, headquarters of the London Assembly.

Millbank Millennium Pier: Millbank Millennium Pier is a pier on the west bank of the River Thames, in London, United Kingdom.  It is served by boats operating under licence from London River Services and is situated between Lambeth Bridge and Vauxhall Bridge on Millbank.  It is accessed from a point adjacent to Millbank Tower and the Tate Britain art gallery.

Westminster tube station: Westminster is a London Underground station in the City of Westminster.  It is served by the Circle, District and Jubilee lines.  On the Circle and District lines, the station is between St. James's Park and Embankment, and on the Jubilee line it is between Green Park and Waterloo.  It is in Travelcard Zone 1.  The station is located at the corner of Bridge Street and Victoria Embankment and is close to the Houses of Parliament, Westminster Abbey, Parliament Square, Whitehall, Westminster Bridge, and the London Eye.  Also close by are Downing Street, the Cenotaph, Westminster Millennium Pier, the Treasury, the Foreign and Commonwealth Office, and the Supreme Court.

London Bridge Wharf: London Bridge Wharf was a wharf in the City of London located alongside London Bridge, just to the east of the north end of the bridge.  It stood below the Adelaide Buildings and their 1925 replacement, Adelaide House.  The wharf was constructed on the site of the London Bridge Waterworks, which had been demolished along with Old London Bridge in 1832.  It originally handled general cargo and also passenger steamships, such as the vessels of the New Medway Steam Packet Company, which offered daily "sea cruises" along the North Kent and Essex coasts.

Tower Millennium Pier: Tower Millennium Pier is a pier on the River Thames, in London, UK.  It is operated by London River Services and served by various river transport and cruise operators.  The pier is close to Tower Bridge and is situated immediately adjacent to the Tower of London, next to the Traitors' Gate.

Boadicea and Her Daughters: Boadicea and Her Daughters is a bronze sculptural group in London featuring Boudica, queen of the Celtic Iceni tribe who led an uprising in Roman Britain.  It is located to the north side of the western end of Westminster Bridge, near Portcullis House and Westminster Pier, facing Big Ben and the Palace of Westminster across the road.  It is considered the "magnum opus" of its sculptor, the English artist and engineer Thomas Thornycroft.  Thornycroft worked on it from 1856 until shortly before his death in 1885, sometimes assisted by his son William Hamo Thornycroft, but it was not erected in its current position until 1902.

Big Ben: Big Ben is the nickname for the Great Bell of the clock at the north end of the Palace of Westminster in London and is usually extended to refer to both the clock and the clock tower as well.  The tower is officially known as Elizabeth Tower, renamed to celebrate the Diamond Jubilee of Elizabeth II in 2012; previously, it was known simply as the Clock Tower.

London Eye Pier: The London Eye Pier (or Waterloo Millennium Pier) is directly in front of the London Eye Ferris wheel on the South Bank of the River Thames in Central London, England.

Blackfriars Millennium Pier: Blackfriars Millennium Pier is a pier on the River Thames, in the Blackfriars area of London, United Kingdom.  It is served by boats operating under licence from London River Services and is situated on the north bank of the Thames, adjacent to Blackfriars Bridge.

Westminster Millennium Pier: Westminster Millennium Pier is a pier on the River Thames, in the City of Westminster in London, UK.  It is operated by London River Services and served by various river transport and cruise operators.  It is located next to Westminster Bridge on the north bank of the Thames, and is close to one of London's most promininent landmarks, Big Ben.

Supporting paragraphs: Westminster Millennium Pier Big Ben
Answer: Westminster Bridge