A、In the morning. B、In the afternoon. C、In the evening. D、The whole day. A

April Fool’s Day is traditionally a day to play practical jokes on others, send people on fool’s errands, and fool the unsuspecting. No one knows how this holiday began but it was thought to have originated in France. April Fool’s Day is a "for-fun-only" observance. Nobody is expected to buy gifts or to take their "significant other" out to eat in a fancy restaurant. Nobody gets off work or school. It’s simply a fun little holiday, but a holiday on which one must remain forever vigilant, for he may be the next April Fool!
    Each country celebrates April Fool’s differently. In France, the April Fool’s is called "April Fish" (Poisson d’Avril). The French fool their friends by taping a paper fish to their friends’ backs and when some discover this trick, they yell "Poisson d’Avril!".
    In England, tricks can be played only in the morning. If a trick is played on you, you are a "noodle". In Scotland, April Fool’s Day is 48 hours long and you are called an "April Gowk", which is another name for a cuckoo bird. The second day in Scotland’s April Fool’s is called Tally Day and is dedicated to pranks involving the buttocks. Tally Day’s gift to posterior posterity is the still-hilarious "Kick Me" sign.