Answer:
A continuous transmission of energy from one location to the next.
Step-by-step explanation:
Wave is a disturbance which continuously transmit energy from one location to another. It does not transmit any mass. There are many types of waves like mechanical wave, electromagnetic wave, gravitational waves etc.
The speed of a wave is given by :

is the frequency of wave
is the wavelength of the wave
So, the correct option is (d) "a continuous transmission of energy from one location to the next".