time delay of the reflected waves. refraction of the transmitted waves. direction of the transmitted waves. interference of the transmitted and reflected waves.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Sonar equipment sends waves into deep water and measures the
Possibilities:
- time delay of the reflected waves.
- refraction of the transmitted waves.
- direction of the transmitted waves.
- interference of the transmitted and reflected waves.

time delay of the reflected waves.