Questions 11 to 13 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.
Now, listen to the passage.
According to the passage, which of the following statements is CORRECT

A．Predators usually sleep for a longer time than preys do.
B．Cats and dogs are not very responsive to a sound when they are sleeping.
C．Smart animals such as dolphins and whales are less frequently immobilized by deep sleep.
D．Young predators may become immobilized when in danger because it is difficult for them to keep quiet.