Sustainable energy is defined as

• A. a source of energy that has no long-term impact on ecosystems or resources
• B. energy from sustainable materials
• C. a source of energy that has no effect or impact on currents or future resources
• D. energy that never causes emissions

Answer: (C)

Sustainability in energy means using energy in a way that preserves resources and ecosystems for future generations while meeting present needs. Among the options, the one that talks about a source of energy having no effect on currents or future resources lines up with the idea of not exhausting or irreversibly harming what future generations depend on. It highlights preserving future resources, which is at the heart of sustainable thinking.

In reality, no energy source is completely impact-free, but the goal is to minimize long-term harm and keep resources available for the future. The other statements are less aligned with that aim: claiming no long-term impact is too absolute, energy from sustainable materials describes a sourcing detail rather than the sustainability outcome, and energy that never causes emissions ignores the lifecycle emissions that can come from manufacturing, operation, and disposal of energy technologies.