A、Observing the conquest of "Nian". B、Scare the beast "Nian". C、A form to thank the old man. D、Red is the festival color. B对应文中

The Chinese New Year is now popularly known as the Spring Festival because it starts from the Beginning of Spring. Its origin is too old to be traced. Several explanations are hanging around. All agree, however, that the word Nian, which in modem Chinese solely means "year", was originally the name of a monster beast that started to prey on people the night before the beginning of a new year
    One legend goes that the beast Nian had a very big mouth that would swallow a great many people with one bite. People were very seared. One day, an old man came to their rescue, offering to subdue Nian. To Nian he said, "I hear that you are very capable, but can you swallow the other beasts of prey on earth instead of people who are by no means of your worthy opponents?" So, it swallowed many of the beasts of prey on earth that also harassed people and their domestic animals from time to time.
    After that, the old man disappeared riding the beast Nian. He turned out to be an immortal god. Now that Nian is gone and other beasts of prey are ’also scared into forests, people begin to enjoy their peaceful life. Before the old man left, he had told people to put up red paper decorations on their windows and doors at each year’s end to scare a way Nian in case it sneaked back again, because red is the color the beast feared the most.
    From then on, the tradition of observing the conquest of Nian is carried on from generation to generation.