Final answer:
The correct answer is c) endless. Renewable energy sources, like solar, wind, water, and biomass, have an endless supply and are not used up, while non renewable resources, such as fossil fuels, are consumed faster than they can be naturally replaced.
Step-by-step explanation:
Anything c) endless can be replaced or has an endless supply. Renewable sources of energy don't run out.
Renewable energy is a source of energy that is replenished by nature, so that its use can be sustained indefinitely without depletion. An example is solar energy; it is not 'used up' simply by placing a panel in the sunlight. Non renewable resources, in contrast, are consumed faster than they can be replaced. Fossil fuels, such as oil, are considered non renewable because they cannot be replaced as fast as they are consumed. Sustainable alternatives derive from sources like wind, water, solar, and biomass, which are considered renewable because they are not used up and are replenished in a human time scale.