Answer: The correct answer is pulses.
Step-by-step explanation:
Wave is a disturbance which carries energy from one particle to another. Wave is a continuous disturbance.
Pulse is a single disturbance. It travels through one point to another.
Sound wave consists of rarefaction and compression. It need medium to travel.
In the circular wave, the particles move both parallel and perpendicular to the motion of the wave.
Therefore, all waves consist of a continuous series of the pulses.