Many people like to decorate their houses at Christmas time. They decorate the inside of the house and the outside, too. Inside they usually decorate a Christmas tree and the fire-place, if there is one. Outside they place wreaths, ribbons, and colored lights on the door and windows. If there is a tree in front of their house, they place colored lights on it, too.In New York, there is a very tall, beautifully decorated Christmas tree in Rockefeller Center at Christmas time. In Washington, there is also a big decorated tree in front of the White House. People come from many cities to admire the trees and the gaily decorated shop windows on the principal avenues of large cities. Why do people come to big cities such as New York and Washington at Christmas time().

A. They come to admire the trees and the decorated shop windows in these cities.
B. They come to decorate a Christmas tree themselves.
C. They come to have a Christmas eve in the White House with the president.