Which of the following is an example of the Middle Ages architecture?

• The White Tower in the Tower of London
  Explanation:

  "In the Middle Ages, great cathedrals and churches were built, many of which still stand today. The White Tower in the Tower of London is an example of a Norman castle keep, built on the orders of William the Conqueror."
• The Queen's House in Greenwich
• The O2 arena
• The London Eye