A. solar
B. geothermal
C. hydroelectric
D. nuclear
Geothermal energy is the energy stored in the form of heat beneath the surface of the solid earth. According to the kind of sources in which geothermal energy occurs it can be litho geothermal (in hot dry rocks), igneous geothermal (out of magma) pneumo thermal (from hot gases) and hydrogeothermal (from groundwater).
