Answer:
The correct answer is with the help of seismic waves.
Step-by-step explanation:
The majority of what we know about the interior of the Earth is mainly because of the seismic waves. These are the waves of energy, which can be a result of earthquakes. The two prime kinds of seismic waves are the surface waves and the body waves.
The surface waves move only along the Earth's surface, while the body waves move through the interior of the Earth in all the directions. It is the body waves behavior, which has provided the clues to the scientists regarding the composition of the Earth's layers. There are two kinds of body waves, these are the primary and the secondary waves.