How can water in fuel be detected?

Detecting water in fuel is critical for maintaining fuel quality and ensuring the safety of equipment and vehicles that utilize that fuel. The correct approach includes practical and efficient methods, which is why the choice that encompasses the use of water-finding paste, fuel tests, and checking for phase separation is accurate.

Water-finding paste is a useful tool that changes color in the presence of water, providing a clear visual indication of its presence in fuel tanks or containers. Fuel tests can involve several methods, such as checking for sedimentation, which can indicate water contamination. Additionally, phase separation occurs when water and fuel separate into distinct layers, which can happen particularly in fuels like gasoline and ethanol blends. Observing this phenomenon indicates that water is present, as the phases will not mix.

These methods combined provide a comprehensive and practical way to detect water in fuel. In contrast, relying solely on chemical analysis, laboratory testing, or visual inspection does not offer the same immediate and field-applicable insights into water contamination. Thus, option B effectively encompasses multiple reliable techniques used in practice to ensure that fuel quality is monitored effectively.