The correct options are
B Flash floods
C Coastal floods
D River floods
There are three types of floods- flash floods, river floods, and coastal floods. When a flood occurs within six hours of heavy rainfall, it is called a flash flood. When the melting of snow or precipitation over a large catchment causes rivers to overflow, it is called a river flood. If a flood is associated with cyclone, high tides, and tsunami, it is known as coastal flood.