Dolphins communicate using compression waves (longitudinal waves). Some of the sounds dolphins make are outside the range of human hearing.
Upon spotting a hungry shark, dolphin A sends a message to dolphin B. To send this message as effectively as possible, dolphin A would
Question options:
send the message above the water when it jumps because air is more dense than water, and the sound would be louder above the water.
make a higher pitched signal because a higher pitch is a louder sound.
make a softer sound because the shark will not hear the softer signal.
send the message underwater because a more dense medium produces a louder and faster sound.