Questions 21 to 23 are based on the following news items. At the end of the news item, you will be given 15 seconds to answer the questions. Now listen to the news. Why was there still hope of finding the survivors

A．The mudslide is not as serious as the searchers expected.
B．People are more stubborn in disasters than in normal lives.
C．Searchers discovered that under the debris there is enough room to hold people.
D．People heard sound from under the debris.