Which of the following provides lighting for cave divers to explore?

The most effective tool for providing illumination in underwater cave environments is lights. Cave diving often occurs in areas with little to no natural light, making it essential for divers to bring artificial lighting to navigate safely and effectively. Specialized dive lights are designed to function under water, offering bright and focused beams that help divers see their surroundings and avoid hazards.

Using lights enhances visibility, allowing divers to observe the cave's features, locate their dive team members, and safely traverse through dark passages. Proper lighting gear also ensures that divers can communicate visually, as hand signals or light signals can become essential in low-light scenarios.

While other options like glow sticks could provide limited light, they do not offer the same intensity or directional control, which is crucial for safe navigation in challenging environments. Mirrors may redirect existing light but do not produce their own, and sunscreen has no relevance in terms of lighting. Thus, lights are the indispensable choice for cave divers.