Read the passage and choose the correct answer for each question

Christmas is the biggest festival of the year in most of Britain. Celebrations start properly on December 24, Christmas Eve, although there have been several weeks of preparation beforehand. The Christmas tree and all the presents, food, drink and decorations have been bought. Christmas cards have already been sent to friends and relations. About a week before Christmas, people usually put up their decorations and decorate the Christmas tree with lights, various colored decorations and an angel on the top. Family presents are usually put under the tree.
Christmas Day is the biggest day of the holiday. On the Christmas morning (often very early), children open the presents that are in their socks. Some families go to church. The traditional Christmas dinner consists of roast turkey with potatoes and various other vegetables. Before the dinner, people usually pull crackers-small rolls of paper that have gifts, jokes, and party hats inside.

People usually decorate the Christmas tree __________.

• A. 
  on December 24
• B. 
  on December 25
• C. 
  several weeks before Christmas
• D. 
  about a week before Christmas