Much of the general structure and physical properties of the interior of the earth are inferred from: a)deep oil and gas bore holes b)geologic investigations c)analysis of seismic waves d) study of volcanoes

The answer is C

Explanation:

"The general structure and physical properties of the interior of the earth are inferred through the analysis of seismic waves." This is quoted from what I am currently learning and if you were to do proper research it would tell you the same.

How it works.

"These waves are created by the energy released during earthquakes. The path of seismic waves through the earth is recorded by a world-wide network of seismographs which are located at earthquake monitoring facilities. The path of the seismic waves may be traced from an earthquake's epicenter  through the earth as they are received at numerous sites around the world. "Taken from my textbook.