Renewable Nature of Hydro and Tidal Energy

Steps:

• Define renewable energy as sources naturally replenished on a human timescale, like water cycles or tides.
• Analyze hydroelectric power: Relies on flowing water from rain and rivers, which renew via the water cycle.
• Analyze tidal power: Driven by gravitational pull of moon and sun on oceans, recurring predictably without depletion.
• Conclude both qualify as renewable, so answer is yes for both.

Why D is correct:

• Renewable energy definition (IEA standard) includes sources like water and tides that are inexhaustible over human lifetimes, matching both technologies.

Why the others are wrong:

• A: Incorrectly labels hydroelectric as non-renewable, ignoring its reliance on perpetual water cycles.
• B: Blank option provides no answer, failing to address the question.
• C: Wrongly deems tidal non-renewable, despite tides being a constant, gravity-driven phenomenon.

Final answer: D