The correct option is D It uses the heat energy inside the earth's crust to produce energy.
Geothermal energy is thermal energy of the lava stored inside the Earth’s crust. The heat from the earth's core continuously flows outward in the form of hot, liquid rock (magma). But most often the magma remains below the earth's crust, heating nearby rock and groundwater. Some of this hot water travels back up through faults and cracks and reaches the earth's surface as hot springs or geysers, but most of it stays deep underground, trapped in cracks and porous rock known as geothermal reservoirs. Once the hot water or steam travels up the wells to the surface, it can be used to generate electricity in geothermal power plants or for energy saving non-electrical purposes.