Final answer:
4) Lens cleaner solution. Lens cleaner solution is the solution that is commonly used to clean night vision goggle lens. Other options like water, alcohol, and soap may not be suitable.
Step-by-step explanation:
The solution that is commonly used to clean night vision goggle lens is Lens cleaner solution. This solution is specifically designed for cleaning lenses and is safe to use on night vision goggles. It helps to remove dirt, smudges, and fingerprints from the lens surface without causing any damage.
Other options like water, alcohol, and soap may not be suitable for cleaning night vision goggle lens as they can potentially leave residue or damage the lens. It is important to use a solution that is specifically designed for cleaning lenses to ensure proper cleaning and maintenance.