The correct options are
B Volcanic eruptions
C Man-made explosions
D Earthquakes
Seismic waves are usually generated by earthquakes but may also be caused by explosions, volcanic eruptions and landslides.
In case of an earthquake, seismic waves originate from the epicentre. Seismology is the branch of science that deals with the scientific study of earthquakes.
Thunderstorms do not contribute in formation of seismic waves.