题目

People call the Winter Olympics the White Olympics. At this time, they publish(发行) many stamps to mark(标志) the great games. The first stamps came out on January 25th, 1932 in the United States for the 3rd White Olympics. From then on, publishing stamps during the White Olympics became a rule.During the 4th Winter Olympics, people published a group of stamps in November 1936. They drew five rings of Olympics. It was the first time that the rings appeared(出现) on the stamps of the White Olympics. In the 1950s，the stamps of this kind became more colorful. When the White Olympics came如图所示，假如将一个小磁针放在地球的北极点上，那么小磁针的N极将（　　）A．指北B．指南C．竖直向上D．竖直向下