Explanation:

- Option 1: Radio

Solar cells can power small radios, especially in remote areas or during emergencies.

- Option 2: Space probes

Space probes often rely on solar power as a primary energy source due to long missions and distance from Earth.

- Option 3: Lift system

Lift systems typically require significant power and are usually connected to the grid, not solar cells.

? Correct Answer

- Option 4: Artificial satellites

Satellites often use solar panels to harness energy in space, where sunlight is abundant.