What type of energy source can be replenished and is not exhausted by use?

The correct answer is a renewable energy source, which refers to energy derived from resources that are naturally replenished on a human timescale. Examples of renewable energy sources include solar, wind, hydro, geothermal, and biomass. These sources are sustainable because they can be naturally replenished without being depleted. For instance, sunlight will continue to shine, wind will continue to blow, and rivers will flow regardless of how much energy is harnessed from them.

In contrast, fossil fuels and nonrenewable energy sources are formed over millions of years and cannot be replenished quickly. Once extracted and used, they become exhausted, contributing to environmental issues such as pollution and climate change. Nuclear energy, while capable of generating large amounts of power, relies on finite resources of uranium and other materials. Eventually, these resources can also be depleted, making them nonrenewable in practice, even though the energy they produce does not directly deplete a fuel in the same manner as fossil fuels.