Final answer:
The correct answer to the student's question is 'renewable', which refers to natural resources that can be replenished at the same rate as they are consumed, such as sunlight and wind, ensuring sustainability for future generations.
Step-by-step explanation:
A renewable energy source is a natural resource that can be replenished by a natural process. The correct answer to the question is option 1) Renewable. Renewable resources include energy sources such as sunlight, wind, hydropower, and geothermal power. These resources are considered renewable because they are replaced by natural processes as quickly as they are used by humans. Alternative energy sources like wind power and solar power fall under the category of renewable resources. They are key to sustainable energy systems because they can meet today's needs without compromising the ability of future generations to meet their energy needs.