Unless it is unavoidable do not jump from a place higher than 5 meters into the water. Try to minimize the shook of sudden cold immersion. When should the said caution be taken into account?（）.
A.The mariners try to put out fire on board of vessel
B.The people on board try to survive themselves from a ship in perils
C.The salvors take actions to rescue the survivors at sea
D.The pilot come on board from his boat in bad weather
