Which of the following is a source of renewable energy?

Geothermal power is a source of renewable energy because it harnesses heat generated and stored within the Earth. This energy source is sustainable, as the heat is continuously produced and can be replenished over time. Geothermal energy systems can be used for heating, electricity generation, and direct use applications, and they produce minimal greenhouse gas emissions during operation, making them environmentally friendly.

In contrast, natural gas, nuclear power, and coal are categorized as non-renewable sources. Natural gas and coal are fossil fuels derived from the earth's geological processes that take millions of years to form, which means they are finite resources subject to depletion as they are consumed. Nuclear power, while it can produce large amounts of energy efficiently, relies on uranium, which is also a non-renewable resource since it is mined and processed. Therefore, geothermal power stands out as a sustainable alternative within the realm of energy sources.