What must be provided to prevent the flow or accumulation of flammable materials under cylinders?

Preventing the flow or accumulation of flammable materials under cylinders is critical for ensuring safety in environments where compressed natural gas (CNG) is stored or utilized. The correct answer emphasizes the necessity of having a defined and effective means to prevent the accumulation of such materials.

This approach is crucial because, in the event of a leak or spill, flammable materials could create a dangerous situation, risking explosions or fires. By establishing a means to prevent this flow or accumulation, safety protocols are adhered to, minimizing possible hazards.

While options like a drainage system or a concrete platform can contribute to safety, they do not directly address the specific requirement of preventing flammable materials from accumulating. The choice of a barrier made of sandbags, while potentially useful in certain scenarios, also doesn’t encompass the broader necessity of ensuring there are systems in place specifically designed to prevent the presence of flammable materials under cylinders. The selected option is the most comprehensive and directly aligns with the safety measures required in handling and storing CNG properly.