Answer:
The wave is being absorbed.
Step-by-step explanation:
When a wave transfers its energy to a substance or material it penetrates means that the wave energy is being absorbed by the matter. During wave absorption, the energy present in the wave is transferred and the wave energy penetrates inside the body of the material. The wave is transferring its energy to the atoms and molecules of matter that make up the absorbing material so we can conclude that wave is being absorbed by the matter.