In volcanic areas, groundwater heated by magma is a source of
a. lava flows.
b. silica.
c. geothermal energy.
d. pyroclastic flows.

c. geothermal energy.

In volcanic areas, groundwater heated by magma is a source of geothermal energy.

Explanation:

Geothermal energy refers to the heat derived from the earth. This heat is obtained from the original formation of the planet and the decomposed radioactive elements in the Earth’s crust. It is a renewable source of energy due to the fact that heat is continuously produced inside the earth. It is used for heating, bathing and also for generating clean electricity. Its resources range from shallow ground to hot water and hot rock that can be found a few miles below the earth's surface and extending down far to the extreme high temperatures of molten rock known as magma.