Wells can be drilled into the earth to harvest energy.
The correct option is B geothermal
The heat energy generated inside the Earth due to decay of radioactive elements is called geothermal energy. The hot springs on the Earth's surface can be used to harvest geothermal energy. The steam from the hotsprings is used to rotate the turbines to produce electricity. In the absence of natural hot springs, wells are drilled into the Earth to trap the heat energy.