Which of the following statements is true regarding oxygen cylinders?

The statement that "oxygen supports combustion" accurately reflects the role of oxygen in the combustion process. While oxygen itself is not flammable, it is essential for the combustion of other materials. When oxygen is present, it can accelerate and support the burning of fuels, making fires burn hotter and faster. Understanding this property is crucial for safety, especially in environments where flammable materials are present, such as construction sites.

The mention of oxygen being highly flammable is misleading since gases like oxygen do not ignite on their own; rather, they promote the combustion of other substances. The requirement for oxygen to be stored in closed containers is also important, but the primary characteristic that underscores fire safety and the relationship between oxygen and combustion is its role in supporting combustion. Additionally, oxygen is typically stored at high pressures to ensure better storage efficiency, rather than lower pressures.