Which of the following is a correct marking for enriched air cylinders?

The correct marking for enriched air cylinders is the yellow with a green band marked "Enriched Air." This marking is standardized to help identify cylinders filled with enriched air (nitrox) clearly and safely. It is designed to provide a clear visual indication that the tank contains a higher percentage of oxygen, which is essential for divers to recognize to avoid potential oxygen toxicity and to follow the proper procedures associated with using enriched air.

In the context of diving safety, having a distinct color coding system helps divers quickly and reliably identify the type of gas contained within the cylinder, ensuring that they use the appropriate gas for their dives. This color combination (yellow with a green band) allows for immediate recognition in various diving environments, promoting safe diving practices.

The other options do not represent the correct markings established for enriched air cylinders, which is critical for maintaining safety and avoiding confusion during diving operations.