单项选择题 Which signal is recognized as a distress signal?（）.

单项选择题 A RADIO SIGNAL FROM A DISTRESSED VESSEL AUTOMATICALLY DIRECTED TO A RCC GIVING POSITION，IDENTIFICATION，COURSE AND SPEED OF THE VESSEL AS WELL AS THE NATURE OF DISTRESS is known as（）.

单项选择题 You receive a call from the MSA OF CHINA addressed to all stations. The call begins with the words Pan-Pan (3 times). Which type of emergency signal would this be?（）.