Which One of the Following Is True Regarding Tsunamis

Which one of the following is true regarding tsunamis?

A) They travel as deep-water waves at speeds greater than the speed of sound in water so they hit the coast followed by a massive rumble like a sonic boom.
B) Their wave heights decrease and wavelengths increase as they move into shallower water.
C) They are started by fault-induced, horizontal shifts in the sea floor that suddenly propel great masses of water upwards like spreading ripples in all directions.
D) They occur in the open ocean like fast surface waves travelling at hundreds of kilometres per hour, wavelengths are hundreds of kilometres, and wave heights < a metre.