Which of the following is categorized as a flammable liquid?

Diesel fuel is categorized as a flammable liquid because it has a flash point that can ignite under specific conditions, such as exposure to an open flame or a spark. Flammable liquids are typically characterized by having a relatively low flash point, which is the temperature at which they can vaporize and form ignitable mixtures with air. Diesel fuel, while less volatile than gasoline, still poses a fire risk and requires careful handling and storage to prevent accidents.

In contrast, water is a non-flammable substance and cannot ignite. Oxygen, although essential for combustion, is not a flammable substance by itself; it supports the process of burning. Cement is a solid material used for construction and does not possess flammable properties. Understanding these distinctions is crucial for safety in environments where flammable materials may be present.